20804731 has 2 divisors, whose sum is σ = 20804732. Its totient is φ = 20804730.

The previous prime is 20804723. The next prime is 20804737. The reversal of 20804731 is 13740802.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20804731 - 2³ = 20804723 is a prime.

It is a super-2 number, since 2×20804731² = 865673663964722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20804696 and 20804705.

It is not a weakly prime, because it can be changed into another prime (20804737) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10402365 + 10402366.

It is an arithmetic number, because the mean of its divisors is an integer number (10402366).

Almost surely, 2^20804731 is an apocalyptic number.

20804731 is a deficient number, since it is larger than the sum of its proper divisors (1).

20804731 is an equidigital number, since it uses as much as digits as its factorization.

20804731 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 20804731 is about 4561.2203410929. The cubic root of 20804731 is about 275.0346226381.

The spelling of 20804731 in words is "twenty million, eight hundred four thousand, seven hundred thirty-one".