1640994432 has 512 divisors, whose sum is σ = 6016204800. Its totient is φ = 383201280.

The previous prime is 1640994403. The next prime is 1640994457. The reversal of 1640994432 is 2344990461.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 12921153 + ... + 12921279.

It is an arithmetic number, because the mean of its divisors is an integer number (11750400).

Almost surely, 2^1640994432 is an apocalyptic number.

1640994432 is a gapful number since it is divisible by the number (12) 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 1640994432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3008102400).

1640994432 is an abundant number, since it is smaller than the sum of its proper divisors (4375210368).

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

1640994432 is a wasteful number, since it uses less digits than its factorization.

1640994432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204 (or 192 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 42.

The square root of 1640994432 is about 40509.1894759695. The cubic root of 1640994432 is about 1179.5120150192.

The spelling of 1640994432 in words is "one billion, six hundred forty million, nine hundred ninety-four thousand, four hundred thirty-two".