20297831 has 2 divisors, whose sum is σ = 20297832. Its totient is φ = 20297830.

The previous prime is 20297807. The next prime is 20297861. The reversal of 20297831 is 13879202.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20297831 is a prime.

It is a super-2 number, since 2×20297831² = 824003886609122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20297861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10148915 + 10148916.

It is an arithmetic number, because the mean of its divisors is an integer number (10148916).

Almost surely, 2^20297831 is an apocalyptic number.

20297831 is a deficient number, since it is larger than the sum of its proper divisors (1).

20297831 is an equidigital number, since it uses as much as digits as its factorization.

20297831 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 20297831 is about 4505.3114209786. The cubic root of 20297831 is about 272.7825243648.

The spelling of 20297831 in words is "twenty million, two hundred ninety-seven thousand, eight hundred thirty-one".