20974497280 has 80 divisors (see below), whose sum is σ = 54861493104. Its totient is φ = 7627079680.

The previous prime is 20974497251. The next prime is 20974497281. The reversal of 20974497280 is 8279447902.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×20974497280² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20974497281) 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, 344257 + ... + 400576.

Almost surely, 2^20974497280 is an apocalyptic number.

20974497280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20974497280 is an abundant number, since it is smaller than the sum of its proper divisors (33886995824).

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

20974497280 is an equidigital number, since it uses as much as digits as its factorization.

20974497280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 744867 (or 744851 counting only the distinct ones).

The product of its (nonzero) digits is 2032128, while the sum is 52.

The spelling of 20974497280 in words is "twenty billion, nine hundred seventy-four million, four hundred ninety-seven thousand, two hundred eighty".