20511977472 has 312 divisors, whose sum is σ = 70074332640. Its totient is φ = 5656412160.

The previous prime is 20511977471. The next prime is 20511977477. The reversal of 20511977472 is 27477911502.

20511977472 is a `hidden beast` number, since 2 + 0 + 511 + 97 + 7 + 47 + 2 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20511977471) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7482022 + ... + 7484762.

It is an arithmetic number, because the mean of its divisors is an integer number (224597220).

Almost surely, 2^20511977472 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20511977472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35037166320).

20511977472 is an abundant number, since it is smaller than the sum of its proper divisors (49562355168).

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

20511977472 is a wasteful number, since it uses less digits than its factorization.

20511977472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2807 (or 2782 counting only the distinct ones).

The product of its (nonzero) digits is 246960, while the sum is 45.

The spelling of 20511977472 in words is "twenty billion, five hundred eleven million, nine hundred seventy-seven thousand, four hundred seventy-two".