28307831 has 2 divisors, whose sum is σ = 28307832. Its totient is φ = 28307830.

The previous prime is 28307827. The next prime is 28307837. The reversal of 28307831 is 13870382.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28307831 - 2² = 28307827 is a prime.

It is a super-2 number, since 2×28307831² = 1602666591849122, which contains 22 as substring.

It is a Chen prime.

It is equal to p_1759424 and since 28307831 and 1759424 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28307837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14153915 + 14153916.

It is an arithmetic number, because the mean of its divisors is an integer number (14153916).

Almost surely, 2^28307831 is an apocalyptic number.

28307831 is a deficient number, since it is larger than the sum of its proper divisors (1).

28307831 is an equidigital number, since it uses as much as digits as its factorization.

28307831 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 28307831 is about 5320.5104078462. The cubic root of 28307831 is about 304.7676488915.

The spelling of 28307831 in words is "twenty-eight million, three hundred seven thousand, eight hundred thirty-one".