20857520980 has 24 divisors (see below), whose sum is σ = 43803722088. Its totient is φ = 8342450688.

The previous prime is 20857520947. The next prime is 20857520993. The reversal of 20857520980 is 8902575802.

It can be written as a sum of positive squares in 4 ways, for example, as 3525271876 + 17332249104 = 59374^2 + 131652^2 .

It is a super-2 number, since 2×20857520980² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20857520980.

It is a congruent number.

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, 410752 + ... + 458728.

It is an arithmetic number, because the mean of its divisors is an integer number (1825155087).

Almost surely, 2^20857520980 is an apocalyptic number.

20857520980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20857520980 is an abundant number, since it is smaller than the sum of its proper divisors (22946201108).

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

20857520980 is a wasteful number, since it uses less digits than its factorization.

20857520980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69723 (or 69721 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 46.

The spelling of 20857520980 in words is "twenty billion, eight hundred fifty-seven million, five hundred twenty thousand, nine hundred eighty".