1640894423040 has 560 divisors, whose sum is σ = 6041991159072. Its totient is φ = 425713729536.

The previous prime is 1640894423033. The next prime is 1640894423041. The reversal of 1640894423040 is 403244980461.

1640894423040 is a `hidden beast` number, since 1 + 6 + 408 + 9 + 4 + 4 + 230 + 4 + 0 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640894423041) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 122750437 + ... + 122763803.

Almost surely, 2^{1640894423040} is an apocalyptic number.

1640894423040 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 1640894423040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3020995579536).

1640894423040 is an abundant number, since it is smaller than the sum of its proper divisors (4401096736032).

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

1640894423040 is an equidigital number, since it uses as much as digits as its factorization.

1640894423040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13447 (or 13414 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 45.

The spelling of 1640894423040 in words is "one trillion, six hundred forty billion, eight hundred ninety-four million, four hundred twenty-three thousand, forty".