28912531 has 2 divisors, whose sum is σ = 28912532. Its totient is φ = 28912530.

The previous prime is 28912523. The next prime is 28912571. The reversal of 28912531 is 13521982.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28912531 - 2³ = 28912523 is a prime.

It is a super-2 number, since 2×28912531² = 1671868897651922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28912493 and 28912502.

It is not a weakly prime, because it can be changed into another prime (28912571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14456265 + 14456266.

It is an arithmetic number, because the mean of its divisors is an integer number (14456266).

Almost surely, 2^28912531 is an apocalyptic number.

28912531 is a deficient number, since it is larger than the sum of its proper divisors (1).

28912531 is an equidigital number, since it uses as much as digits as its factorization.

28912531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4320, while the sum is 31.

The square root of 28912531 is about 5377.0373813095. The cubic root of 28912531 is about 306.9224835856.

The spelling of 28912531 in words is "twenty-eight million, nine hundred twelve thousand, five hundred thirty-one".