20766880 has 24 divisors (see below), whose sum is σ = 49062132. Its totient is φ = 8306688.

The previous prime is 20766859. The next prime is 20766887. The reversal of 20766880 is 8866702.

It can be written as a sum of positive squares in 2 ways, for example, as 20466576 + 300304 = 4524^2 + 548^2 .

It is not an unprimeable number, because it can be changed into a prime (20766887) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64737 + ... + 65056.

Almost surely, 2^20766880 is an apocalyptic number.

20766880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20766880 is an abundant number, since it is smaller than the sum of its proper divisors (28295252).

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

20766880 is a wasteful number, since it uses less digits than its factorization.

20766880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129808 (or 129800 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 37.

The square root of 20766880 is about 4557.0692336193. The cubic root of 20766880 is about 274.8677270215.

The spelling of 20766880 in words is "twenty million, seven hundred sixty-six thousand, eight hundred eighty".