28209131 has 2 divisors, whose sum is σ = 28209132. Its totient is φ = 28209130.

The previous prime is 28209121. The next prime is 28209149. The reversal of 28209131 is 13190282.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28209131 - 2¹⁰ = 28208107 is a prime.

It is a super-2 number, since 2×28209131² = 1591510143550322, which contains 22 as substring.

It is a Chen prime.

It is equal to p_1753613 and since 28209131 and 1753613 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28209131.

It is not a weakly prime, because it can be changed into another prime (28209121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14104565 + 14104566.

It is an arithmetic number, because the mean of its divisors is an integer number (14104566).

Almost surely, 2^28209131 is an apocalyptic number.

28209131 is a deficient number, since it is larger than the sum of its proper divisors (1).

28209131 is an equidigital number, since it uses as much as digits as its factorization.

28209131 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 28209131 is about 5311.2268827456. The cubic root of 28209131 is about 304.4130285848.

The spelling of 28209131 in words is "twenty-eight million, two hundred nine thousand, one hundred thirty-one".