28911939 has 16 divisors (see below), whose sum is σ = 46375680. Its totient is φ = 15651360.

The previous prime is 28911919. The next prime is 28911941. The reversal of 28911939 is 93911982.

It is not a de Polignac number, because 28911939 - 2¹¹ = 28909891 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28911939.

It is not an unprimeable number, because it can be changed into a prime (28911919) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35832 + ... + 36629.

It is an arithmetic number, because the mean of its divisors is an integer number (2898480).

Almost surely, 2^28911939 is an apocalyptic number.

28911939 is a deficient number, since it is larger than the sum of its proper divisors (17463741).

28911939 is a wasteful number, since it uses less digits than its factorization.

28911939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72490.

The product of its digits is 34992, while the sum is 42.

The square root of 28911939 is about 5376.9823321265. The cubic root of 28911939 is about 306.9203887690.

The spelling of 28911939 in words is "twenty-eight million, nine hundred eleven thousand, nine hundred thirty-nine".