20513355264 has 120 divisors (see below), whose sum is σ = 59375353752. Its totient is φ = 6817873920.

The previous prime is 20513355251. The next prime is 20513355383. The reversal of 20513355264 is 46255331502.

20513355264 is a `hidden beast` number, since 2 + 0 + 513 + 35 + 52 + 64 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1620319 + ... + 1632929.

Almost surely, 2^20513355264 is an apocalyptic number.

20513355264 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20513355264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29687676876).

20513355264 is an abundant number, since it is smaller than the sum of its proper divisors (38861998488).

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

20513355264 is a wasteful number, since it uses less digits than its factorization.

20513355264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12988 (or 12969 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 36.

Adding to 20513355264 its reverse (46255331502), we get a palindrome (66768686766).

The spelling of 20513355264 in words is "twenty billion, five hundred thirteen million, three hundred fifty-five thousand, two hundred sixty-four".