20931577850 has 48 divisors (see below), whose sum is σ = 39128076000. Its totient is φ = 8330738880.

The previous prime is 20931577841. The next prime is 20931577853. The reversal of 20931577850 is 5877513902.

It is a super-2 number, since 2×20931577850² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20931577795 and 20931577804.

It is not an unprimeable number, because it can be changed into a prime (20931577853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10738676 + ... + 10740624.

It is an arithmetic number, because the mean of its divisors is an integer number (815168250).

Almost surely, 2^20931577850 is an apocalyptic number.

20931577850 is a deficient number, since it is larger than the sum of its proper divisors (18196498150).

20931577850 is a wasteful number, since it uses less digits than its factorization.

20931577850 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2927 (or 2922 counting only the distinct ones).

The product of its (nonzero) digits is 529200, while the sum is 47.

The spelling of 20931577850 in words is "twenty billion, nine hundred thirty-one million, five hundred seventy-seven thousand, eight hundred fifty".