28440923 has 12 divisors (see below), whose sum is σ = 33206832. Its totient is φ = 24287760.

The previous prime is 28440917. The next prime is 28440941. The reversal of 28440923 is 32904482.

It is not a de Polignac number, because 28440923 - 2⁸ = 28440667 is a prime.

It is a super-2 number, since 2×28440923² = 1617772202183858, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28440923.

It is not an unprimeable number, because it can be changed into a prime (28440943) 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, 14618 + ... + 16448.

It is an arithmetic number, because the mean of its divisors is an integer number (2767236).

Almost surely, 2^28440923 is an apocalyptic number.

28440923 is a deficient number, since it is larger than the sum of its proper divisors (4765909).

28440923 is a wasteful number, since it uses less digits than its factorization.

28440923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2162 (or 2155 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 32.

The square root of 28440923 is about 5333.0031876983. The cubic root of 28440923 is about 305.2445338039.

The spelling of 28440923 in words is "twenty-eight million, four hundred forty thousand, nine hundred twenty-three".