1640503920 has 160 divisors (see below), whose sum is σ = 5570786304. Its totient is φ = 396057600.

The previous prime is 1640503903. The next prime is 1640503937. The reversal of 1640503920 is 293050461.

It is an interprime number because it is at equal distance from previous prime (1640503903) and next prime (1640503937).

It is a super-2 number, since 2×1640503920² = 5382506223070732800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 714294 + ... + 716586.

Almost surely, 2^1640503920 is an apocalyptic number.

1640503920 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 1640503920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2785393152).

1640503920 is an abundant number, since it is smaller than the sum of its proper divisors (3930282384).

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

1640503920 is a wasteful number, since it uses less digits than its factorization.

1640503920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2591 (or 2585 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 30.

The square root of 1640503920 is about 40503.1346935024. The cubic root of 1640503920 is about 1179.3944800981.

The spelling of 1640503920 in words is "one billion, six hundred forty million, five hundred three thousand, nine hundred twenty".