28821725 has 12 divisors (see below), whose sum is σ = 36274464. Its totient is φ = 22711920.

The previous prime is 28821721. The next prime is 28821743. The reversal of 28821725 is 52712882.

It is not a de Polignac number, because 28821725 - 2² = 28821721 is a prime.

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28821721) 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, 6929 + ... + 10278.

It is an arithmetic number, because the mean of its divisors is an integer number (3022872).

Almost surely, 2^28821725 is an apocalyptic number.

28821725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28821725 is a deficient number, since it is larger than the sum of its proper divisors (7452739).

28821725 is a wasteful number, since it uses less digits than its factorization.

28821725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17284 (or 17279 counting only the distinct ones).

The product of its digits is 17920, while the sum is 35.

The square root of 28821725 is about 5368.5868717941. The cubic root of 28821725 is about 306.6008279948.

The spelling of 28821725 in words is "twenty-eight million, eight hundred twenty-one thousand, seven hundred twenty-five".