28979939 has 4 divisors (see below), whose sum is σ = 29245920. Its totient is φ = 28713960.

The previous prime is 28979897. The next prime is 28979957. The reversal of 28979939 is 93997982.

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

It is a cyclic number.

It is not a de Polignac number, because 28979939 - 2²⁰ = 27931363 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28979969) 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, 132827 + ... + 133044.

It is an arithmetic number, because the mean of its divisors is an integer number (7311480).

Almost surely, 2^28979939 is an apocalyptic number.

28979939 is a deficient number, since it is larger than the sum of its proper divisors (265981).

28979939 is a wasteful number, since it uses less digits than its factorization.

28979939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 265980.

The product of its digits is 2204496, while the sum is 56.

The square root of 28979939 is about 5383.3018678131. The cubic root of 28979939 is about 307.1608228385.

The spelling of 28979939 in words is "twenty-eight million, nine hundred seventy-nine thousand, nine hundred thirty-nine".