1640597920 has 288 divisors, whose sum is σ = 4602007872. Its totient is φ = 550158336.

The previous prime is 1640597909. The next prime is 1640597953. The reversal of 1640597920 is 297950461.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 19766199 + ... + 19766281.

It is an arithmetic number, because the mean of its divisors is an integer number (15979194).

Almost surely, 2^1640597920 is an apocalyptic number.

1640597920 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 1640597920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2301003936).

1640597920 is an abundant number, since it is smaller than the sum of its proper divisors (2961409952).

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

1640597920 is a wasteful number, since it uses less digits than its factorization.

1640597920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 184 (or 163 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 43.

The square root of 1640597920 is about 40504.2950808923. The cubic root of 1640597920 is about 1179.4170058928.

The spelling of 1640597920 in words is "one billion, six hundred forty million, five hundred ninety-seven thousand, nine hundred twenty".