20915970456 has 128 divisors (see below), whose sum is σ = 55035417600. Its totient is φ = 6617994240.

The previous prime is 20915970371. The next prime is 20915970457. The reversal of 20915970456 is 65407951902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20915970457) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5318811 + ... + 5322741.

It is an arithmetic number, because the mean of its divisors is an integer number (429964200).

Almost surely, 2^20915970456 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 20915970456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27517708800).

20915970456 is an abundant number, since it is smaller than the sum of its proper divisors (34119447144).

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

20915970456 is a wasteful number, since it uses less digits than its factorization.

20915970456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4129 (or 4125 counting only the distinct ones).

The product of its (nonzero) digits is 680400, while the sum is 48.

The spelling of 20915970456 in words is "twenty billion, nine hundred fifteen million, nine hundred seventy thousand, four hundred fifty-six".