28686431 has 2 divisors, whose sum is σ = 28686432. Its totient is φ = 28686430.

The previous prime is 28686419. The next prime is 28686473. The reversal of 28686431 is 13468682.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28686431 - 2⁶ = 28686367 is a prime.

It is a super-2 number, since 2×28686431² = 1645822647035522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28686491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14343215 + 14343216.

It is an arithmetic number, because the mean of its divisors is an integer number (14343216).

Almost surely, 2^28686431 is an apocalyptic number.

28686431 is a deficient number, since it is larger than the sum of its proper divisors (1).

28686431 is an equidigital number, since it uses as much as digits as its factorization.

28686431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 55296, while the sum is 38.

The square root of 28686431 is about 5355.9715271835. The cubic root of 28686431 is about 306.1203301658.

The spelling of 28686431 in words is "twenty-eight million, six hundred eighty-six thousand, four hundred thirty-one".