1994091840 has 504 divisors, whose sum is σ = 7896548088. Its totient is φ = 460062720.

The previous prime is 1994091829. The next prime is 1994091859. The reversal of 1994091840 is 481904991.

1994091840 is a `hidden beast` number, since 199 + 409 + 18 + 40 = 666.

It can be written as a sum of positive squares in 12 ways, for example, as 588741696 + 1405350144 = 24264^2 + 37488^2 .

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 8274120 + ... + 8274360.

Almost surely, 2^1994091840 is an apocalyptic number.

1994091840 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 1994091840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3948274044).

1994091840 is an abundant number, since it is smaller than the sum of its proper divisors (5902456248).

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

1994091840 is a wasteful number, since it uses less digits than its factorization.

1994091840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 307 (or 281 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The square root of 1994091840 is about 44655.2554577846. The cubic root of 1994091840 is about 1258.6791903818.

The spelling of 1994091840 in words is "one billion, nine hundred ninety-four million, ninety-one thousand, eight hundred forty".