20980621956 has 24 divisors (see below), whose sum is σ = 55948325440. Its totient is φ = 5994463392.

The previous prime is 20980621951. The next prime is 20980621957. The reversal of 20980621956 is 65912608902.

It is not an unprimeable number, because it can be changed into a prime (20980621951) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 124884571 + ... + 124884738.

Almost surely, 2^20980621956 is an apocalyptic number.

It is an amenable number.

20980621956 is an abundant number, since it is smaller than the sum of its proper divisors (34967703484).

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

20980621956 is a wasteful number, since it uses less digits than its factorization.

20980621956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249769323 (or 249769321 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 48.

The spelling of 20980621956 in words is "twenty billion, nine hundred eighty million, six hundred twenty-one thousand, nine hundred fifty-six".