28699131 has 4 divisors (see below), whose sum is σ = 38265512. Its totient is φ = 19132752.

The previous prime is 28699127. The next prime is 28699133. The reversal of 28699131 is 13199682.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 28699131 - 2² = 28699127 is a prime.

It is a super-2 number, since 2×28699131² = 1647280240310322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28699131.

It is not an unprimeable number, because it can be changed into a prime (28699133) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4783186 + ... + 4783191.

It is an arithmetic number, because the mean of its divisors is an integer number (9566378).

Almost surely, 2^28699131 is an apocalyptic number.

28699131 is a deficient number, since it is larger than the sum of its proper divisors (9566381).

28699131 is an equidigital number, since it uses as much as digits as its factorization.

28699131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9566380.

The product of its digits is 23328, while the sum is 39.

The square root of 28699131 is about 5357.1569885528. The cubic root of 28699131 is about 306.1654984966.

The spelling of 28699131 in words is "twenty-eight million, six hundred ninety-nine thousand, one hundred thirty-one".