20772840 has 64 divisors (see below), whose sum is σ = 67988160. Its totient is φ = 5035520.

The previous prime is 20772811. The next prime is 20772847. The reversal of 20772840 is 4827702.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 20772798 and 20772807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20772847) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6549 + ... + 9188.

It is an arithmetic number, because the mean of its divisors is an integer number (1062315).

Almost surely, 2^20772840 is an apocalyptic number.

20772840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20772840 is an abundant number, since it is smaller than the sum of its proper divisors (47215320).

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

20772840 is a wasteful number, since it uses less digits than its factorization.

20772840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15762 (or 15758 counting only the distinct ones).

The product of its (nonzero) digits is 6272, while the sum is 30.

The square root of 20772840 is about 4557.7231157673. The cubic root of 20772840 is about 274.8940197684.

It can be divided in two parts, 20772 and 840, that added together give a palindrome (21612).

The spelling of 20772840 in words is "twenty million, seven hundred seventy-two thousand, eight hundred forty".