20664780780 has 144 divisors (see below), whose sum is σ = 71267618016. Its totient is φ = 4445521920.

The previous prime is 20664780757. The next prime is 20664780791. The reversal of 20664780780 is 8708746602.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 156751 + ... + 256710.

It is an arithmetic number, because the mean of its divisors is an integer number (494914014).

Almost surely, 2^20664780780 is an apocalyptic number.

20664780780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20664780780 is an abundant number, since it is smaller than the sum of its proper divisors (50602837236).

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

20664780780 is a wasteful number, since it uses less digits than its factorization.

20664780780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 413504 (or 413495 counting only the distinct ones).

The product of its (nonzero) digits is 903168, while the sum is 48.

The spelling of 20664780780 in words is "twenty billion, six hundred sixty-four million, seven hundred eighty thousand, seven hundred eighty".