20640692590 has 64 divisors (see below), whose sum is σ = 43298914176. Its totient is φ = 6937362432.

The previous prime is 20640692581. The next prime is 20640692599. The reversal of 20640692590 is 9529604602.

It is an interprime number because it is at equal distance from previous prime (20640692581) and next prime (20640692599).

It is a Smith number, since the sum of its digits (43) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20640692599) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7837914 + ... + 7840546.

It is an arithmetic number, because the mean of its divisors is an integer number (676545534).

Almost surely, 2^20640692590 is an apocalyptic number.

20640692590 is an abundant number, since it is smaller than the sum of its proper divisors (22658221586).

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

20640692590 is a wasteful number, since it uses less digits than its factorization.

20640692590 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4813.

The product of its (nonzero) digits is 233280, while the sum is 43.

The spelling of 20640692590 in words is "twenty billion, six hundred forty million, six hundred ninety-two thousand, five hundred ninety".