28591431 has 16 divisors (see below), whose sum is σ = 42556800. Its totient is φ = 16924320.

The previous prime is 28591403. The next prime is 28591439. The reversal of 28591431 is 13419582.

It is not a de Polignac number, because 28591431 - 2¹¹ = 28589383 is a prime.

It is a super-2 number, since 2×28591431² = 1634939853255522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 28591392 and 28591401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28591439) 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, 8656 + ... + 11493.

It is an arithmetic number, because the mean of its divisors is an integer number (2659800).

Almost surely, 2^28591431 is an apocalyptic number.

28591431 is a deficient number, since it is larger than the sum of its proper divisors (13965369).

28591431 is a wasteful number, since it uses less digits than its factorization.

28591431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20206.

The product of its digits is 8640, while the sum is 33.

The square root of 28591431 is about 5347.0955667540. The cubic root of 28591431 is about 305.7820332516.

The spelling of 28591431 in words is "twenty-eight million, five hundred ninety-one thousand, four hundred thirty-one".