20772820 has 24 divisors (see below), whose sum is σ = 44448264. Its totient is φ = 8151936.

The previous prime is 20772811. The next prime is 20772847. The reversal of 20772820 is 2827702.

It can be written as a sum of positive squares in 4 ways, for example, as 2829124 + 17943696 = 1682^2 + 4236^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8739 + ... + 10858.

It is an arithmetic number, because the mean of its divisors is an integer number (1852011).

Almost surely, 2^20772820 is an apocalyptic number.

20772820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20772820 is an abundant number, since it is smaller than the sum of its proper divisors (23675444).

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

20772820 is a wasteful number, since it uses less digits than its factorization.

20772820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19659 (or 19657 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 28.

The square root of 20772820 is about 4557.7209216888. The cubic root of 20772820 is about 274.8939315461.

The spelling of 20772820 in words is "twenty million, seven hundred seventy-two thousand, eight hundred twenty".