28722500 has 30 divisors (see below), whose sum is σ = 62815830. Its totient is φ = 11488000.

The previous prime is 28722479. The next prime is 28722517. The reversal of 28722500 is 522782.

It can be written as a sum of positive squares in 5 ways, for example, as 15429184 + 13293316 = 3928^2 + 3646^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 28722500.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 3245 + ... + 8244.

It is an arithmetic number, because the mean of its divisors is an integer number (2093861).

Almost surely, 2^28722500 is an apocalyptic number.

28722500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28722500 is an abundant number, since it is smaller than the sum of its proper divisors (34093330).

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

28722500 is a wasteful number, since it uses less digits than its factorization.

28722500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11513 (or 11496 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 26.

The square root of 28722500 is about 5359.3376456424. The cubic root of 28722500 is about 306.2485769752.

The spelling of 28722500 in words is "twenty-eight million, seven hundred twenty-two thousand, five hundred".