28102431 has 12 divisors (see below), whose sum is σ = 43587672. Its totient is φ = 16058448.

The previous prime is 28102427. The next prime is 28102441. The reversal of 28102431 is 13420182.

It is not a de Polignac number, because 28102431 - 2² = 28102427 is a prime.

It is a super-2 number, since 2×28102431² = 1579493256219522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 28102398 and 28102407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28102441) 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, 95440 + ... + 95733.

It is an arithmetic number, because the mean of its divisors is an integer number (3632306).

Almost surely, 2^28102431 is an apocalyptic number.

28102431 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

28102431 is a deficient number, since it is larger than the sum of its proper divisors (15485241).

28102431 is a wasteful number, since it uses less digits than its factorization.

28102431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191190 (or 191183 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 28102431 is about 5301.1726061316. The cubic root of 28102431 is about 304.0287332894.

The spelling of 28102431 in words is "twenty-eight million, one hundred two thousand, four hundred thirty-one".