20745978980 has 24 divisors (see below), whose sum is σ = 43643146680. Its totient is φ = 8283802880.

The previous prime is 20745978971. The next prime is 20745978983. The reversal of 20745978980 is 8987954702.

It can be written as a sum of positive squares in 4 ways, for example, as 48553024 + 20697425956 = 6968^2 + 143866^2 .

It is not an unprimeable number, because it can be changed into a prime (20745978983) 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, 900131 + ... + 922890.

It is an arithmetic number, because the mean of its divisors is an integer number (1818464445).

Almost surely, 2^20745978980 is an apocalyptic number.

20745978980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20745978980 is an abundant number, since it is smaller than the sum of its proper divisors (22897167700).

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

20745978980 is a wasteful number, since it uses less digits than its factorization.

20745978980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1823599 (or 1823597 counting only the distinct ones).

The product of its (nonzero) digits is 10160640, while the sum is 59.

The spelling of 20745978980 in words is "twenty billion, seven hundred forty-five million, nine hundred seventy-eight thousand, nine hundred eighty".