1993454640 has 120 divisors (see below), whose sum is σ = 6728810400. Its totient is φ = 528878592.

The previous prime is 1993454633. The next prime is 1993454647. The reversal of 1993454640 is 464543991.

1993454640 is a `hidden beast` number, since 19 + 93 + 4 + 546 + 4 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (1993454633) and next prime (1993454647).

It is a tau number, because it is divible by the number of its divisors (120).

It is a super-2 number, since 2×1993454640² = 7947722803475059200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (1993454647) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 136324 + ... + 150236.

It is an arithmetic number, because the mean of its divisors is an integer number (56073420).

Almost surely, 2^1993454640 is an apocalyptic number.

1993454640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1993454640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3364405200).

1993454640 is an abundant number, since it is smaller than the sum of its proper divisors (4735355760).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1993454640 is a wasteful number, since it uses less digits than its factorization.

1993454640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14131 (or 14122 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 45.

The square root of 1993454640 is about 44648.1202291877. The cubic root of 1993454640 is about 1258.5451083221.

The spelling of 1993454640 in words is "one billion, nine hundred ninety-three million, four hundred fifty-four thousand, six hundred forty".