20644262860 has 24 divisors (see below), whose sum is σ = 46687795056. Its totient is φ = 7622496960.

The previous prime is 20644262839. The next prime is 20644262893. The reversal of 20644262860 is 6826244602.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39700246 + ... + 39700765.

It is an arithmetic number, because the mean of its divisors is an integer number (1945324794).

Almost surely, 2^20644262860 is an apocalyptic number.

20644262860 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20644262860 is an abundant number, since it is smaller than the sum of its proper divisors (26043532196).

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

20644262860 is a wasteful number, since it uses less digits than its factorization.

20644262860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79401033 (or 79401031 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 40.

The spelling of 20644262860 in words is "twenty billion, six hundred forty-four million, two hundred sixty-two thousand, eight hundred sixty".