28909031 has 2 divisors, whose sum is σ = 28909032. Its totient is φ = 28909030.

The previous prime is 28909021. The next prime is 28909039. The reversal of 28909031 is 13090982.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28909031 is a prime.

It is a super-2 number, since 2×28909031² = 1671464146717922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28909039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14454515 + 14454516.

It is an arithmetic number, because the mean of its divisors is an integer number (14454516).

Almost surely, 2^28909031 is an apocalyptic number.

28909031 is a deficient number, since it is larger than the sum of its proper divisors (1).

28909031 is an equidigital number, since it uses as much as digits as its factorization.

28909031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 28909031 is about 5376.7119134281. The cubic root of 28909031 is about 306.9100982748.

The spelling of 28909031 in words is "twenty-eight million, nine hundred nine thousand, thirty-one".