28406831 has 2 divisors, whose sum is σ = 28406832. Its totient is φ = 28406830.

The previous prime is 28406821. The next prime is 28406837. The reversal of 28406831 is 13860482.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28406831 - 2¹⁴ = 28390447 is a prime.

It is a super-2 number, since 2×28406831² = 1613896094925122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28406837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14203415 + 14203416.

It is an arithmetic number, because the mean of its divisors is an integer number (14203416).

Almost surely, 2^28406831 is an apocalyptic number.

28406831 is a deficient number, since it is larger than the sum of its proper divisors (1).

28406831 is an equidigital number, since it uses as much as digits as its factorization.

28406831 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 28406831 is about 5329.8059064097. The cubic root of 28406831 is about 305.1225199784.

The spelling of 28406831 in words is "twenty-eight million, four hundred six thousand, eight hundred thirty-one".