28206431 has 12 divisors (see below), whose sum is σ = 32638200. Its totient is φ = 24290640.

The previous prime is 28206427. The next prime is 28206433. The reversal of 28206431 is 13460282.

It is not a de Polignac number, because 28206431 - 2² = 28206427 is a prime.

It is a super-2 number, since 2×28206431² = 1591205499515522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28206431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28206433) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3836 + ... + 8433.

It is an arithmetic number, because the mean of its divisors is an integer number (2719850).

Almost surely, 2^28206431 is an apocalyptic number.

28206431 is a deficient number, since it is larger than the sum of its proper divisors (4431769).

28206431 is a wasteful number, since it uses less digits than its factorization.

28206431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12310 (or 12299 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 28206431 is about 5310.9726981034. The cubic root of 28206431 is about 304.4033161102.

The spelling of 28206431 in words is "twenty-eight million, two hundred six thousand, four hundred thirty-one".