28972440 has 96 divisors (see below), whose sum is σ = 107621280. Its totient is φ = 6621696.

The previous prime is 28972423. The next prime is 28972451. The reversal of 28972440 is 4427982.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 28972395 and 28972404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3229 + ... + 8268.

It is an arithmetic number, because the mean of its divisors is an integer number (1121055).

Almost surely, 2^28972440 is an apocalyptic number.

28972440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28972440 is an abundant number, since it is smaller than the sum of its proper divisors (78648840).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28972440 is a wasteful number, since it uses less digits than its factorization.

28972440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11521 (or 11514 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 28972440 is about 5382.6053171304. The cubic root of 28972440 is about 307.1343263746.

The spelling of 28972440 in words is "twenty-eight million, nine hundred seventy-two thousand, four hundred forty".