28390971 has 16 divisors (see below), whose sum is σ = 44755200. Its totient is φ = 15663648.

The previous prime is 28390939. The next prime is 28390979. The reversal of 28390971 is 17909382.

It is not a de Polignac number, because 28390971 - 2⁵ = 28390939 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28390979) 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, 22701 + ... + 23918.

It is an arithmetic number, because the mean of its divisors is an integer number (2797200).

Almost surely, 2^28390971 is an apocalyptic number.

28390971 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

28390971 is a deficient number, since it is larger than the sum of its proper divisors (16364229).

28390971 is a wasteful number, since it uses less digits than its factorization.

28390971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46658.

The product of its (nonzero) digits is 27216, while the sum is 39.

The square root of 28390971 is about 5328.3178396188. The cubic root of 28390971 is about 305.0657244368.

The spelling of 28390971 in words is "twenty-eight million, three hundred ninety thousand, nine hundred seventy-one".