20612731 has 4 divisors (see below), whose sum is σ = 20624032. Its totient is φ = 20601432.

The previous prime is 20612723. The next prime is 20612741. The reversal of 20612731 is 13721602.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20612731 - 2³ = 20612723 is a prime.

It is a super-2 number, since 2×20612731² = 849769358556722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20612741) 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, 2220 + ... + 6793.

It is an arithmetic number, because the mean of its divisors is an integer number (5156008).

Almost surely, 2^20612731 is an apocalyptic number.

20612731 is a deficient number, since it is larger than the sum of its proper divisors (11301).

20612731 is an equidigital number, since it uses as much as digits as its factorization.

20612731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11300.

The product of its (nonzero) digits is 504, while the sum is 22.

The square root of 20612731 is about 4540.1245577627. The cubic root of 20612731 is about 274.1859385797.

The spelling of 20612731 in words is "twenty million, six hundred twelve thousand, seven hundred thirty-one".