1640891500 has 24 divisors (see below), whose sum is σ = 3583708128. Its totient is φ = 656356400.

The previous prime is 1640891443. The next prime is 1640891531. The reversal of 1640891500 is 51980461.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1640392 + ... + 1641391.

It is an arithmetic number, because the mean of its divisors is an integer number (149321172).

Almost surely, 2^1640891500 is an apocalyptic number.

1640891500 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1640891500 is an abundant number, since it is smaller than the sum of its proper divisors (1942816628).

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

1640891500 is a wasteful number, since it uses less digits than its factorization.

1640891500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3281802 (or 3281790 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 34.

The square root of 1640891500 is about 40507.9189788861. The cubic root of 1640891500 is about 1179.4873527236.

The spelling of 1640891500 in words is "one billion, six hundred forty million, eight hundred ninety-one thousand, five hundred".