20772731 has 16 divisors (see below), whose sum is σ = 24520704. Its totient is φ = 17229024.

The previous prime is 20772709. The next prime is 20772751. The reversal of 20772731 is 13727702.

It is a cyclic number.

It is not a de Polignac number, because 20772731 - 2⁶ = 20772667 is a prime.

It is a super-2 number, since 2×20772731² = 863012706396722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20772694 and 20772703.

It is not an unprimeable number, because it can be changed into a prime (20772751) 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, 33581 + ... + 34193.

It is an arithmetic number, because the mean of its divisors is an integer number (1532544).

Almost surely, 2^20772731 is an apocalyptic number.

20772731 is a deficient number, since it is larger than the sum of its proper divisors (3747973).

20772731 is a wasteful number, since it uses less digits than its factorization.

20772731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 770.

The product of its (nonzero) digits is 4116, while the sum is 29.

The square root of 20772731 is about 4557.7111580266. The cubic root of 20772731 is about 274.8935389562.

The spelling of 20772731 in words is "twenty million, seven hundred seventy-two thousand, seven hundred thirty-one".