28389631 has 2 divisors, whose sum is σ = 28389632. Its totient is φ = 28389630.

The previous prime is 28389623. The next prime is 28389701. The reversal of 28389631 is 13698382.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28389631 - 2³ = 28389623 is a prime.

It is a super-2 number, since 2×28389631² = 1611942296632322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28389601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14194815 + 14194816.

It is an arithmetic number, because the mean of its divisors is an integer number (14194816).

Almost surely, 2^28389631 is an apocalyptic number.

28389631 is a deficient number, since it is larger than the sum of its proper divisors (1).

28389631 is an equidigital number, since it uses as much as digits as its factorization.

28389631 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 62208, while the sum is 40.

The square root of 28389631 is about 5328.1920948855. The cubic root of 28389631 is about 305.0609248533.

The spelling of 28389631 in words is "twenty-eight million, three hundred eighty-nine thousand, six hundred thirty-one".