20555371720 has 32 divisors (see below), whose sum is σ = 49807248120. Its totient is φ = 7589675520.

The previous prime is 20555371693. The next prime is 20555371747. The reversal of 20555371720 is 2717355502.

It is an interprime number because it is at equal distance from previous prime (20555371693) and next prime (20555371747).

It can be written as a sum of positive squares in 4 ways, for example, as 8207272836 + 12348098884 = 90594^2 + 111122^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20555371720.

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, 19764261 + ... + 19765300.

Almost surely, 2^20555371720 is an apocalyptic number.

20555371720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20555371720 is an abundant number, since it is smaller than the sum of its proper divisors (29251876400).

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

20555371720 is a wasteful number, since it uses less digits than its factorization.

20555371720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39529585 (or 39529581 counting only the distinct ones).

The product of its (nonzero) digits is 73500, while the sum is 37.

The spelling of 20555371720 in words is "twenty billion, five hundred fifty-five million, three hundred seventy-one thousand, seven hundred twenty".