28409031 has 24 divisors (see below), whose sum is σ = 47698560. Its totient is φ = 15956496.

The previous prime is 28408999. The next prime is 28409089. The reversal of 28409031 is 13090482.

28409031 = 1418² + 1419² + ... + 1431².

It is not a de Polignac number, because 28409031 - 2⁵ = 28408999 is a prime.

It is a super-2 number, since 2×28409031² = 1614146084717922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28408986 and 28409004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28409131) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 105 + ... + 7538.

It is an arithmetic number, because the mean of its divisors is an integer number (1987440).

Almost surely, 2^28409031 is an apocalyptic number.

28409031 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

28409031 is a deficient number, since it is larger than the sum of its proper divisors (19289529).

28409031 is a wasteful number, since it uses less digits than its factorization.

28409031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7715 (or 7712 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 28409031 is about 5330.0122889164. The cubic root of 28409031 is about 305.1303966309.

The spelling of 28409031 in words is "twenty-eight million, four hundred nine thousand, thirty-one".