28939691 has 6 divisors (see below), whose sum is σ = 31809876. Its totient is φ = 26308700.

The previous prime is 28939637. The next prime is 28939697. The reversal of 28939691 is 19693982.

It is not a de Polignac number, because 28939691 - 2¹⁸ = 28677547 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28939697) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 119465 + ... + 119706.

It is an arithmetic number, because the mean of its divisors is an integer number (5301646).

Almost surely, 2^28939691 is an apocalyptic number.

28939691 is a deficient number, since it is larger than the sum of its proper divisors (2870185).

28939691 is a wasteful number, since it uses less digits than its factorization.

28939691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239193 (or 239182 counting only the distinct ones).

The product of its digits is 209952, while the sum is 47.

The square root of 28939691 is about 5379.5623427933. The cubic root of 28939691 is about 307.0185596408.

The spelling of 28939691 in words is "twenty-eight million, nine hundred thirty-nine thousand, six hundred ninety-one".