28749690 has 24 divisors (see below), whose sum is σ = 74749428. Its totient is φ = 7666560.

The previous prime is 28749689. The next prime is 28749713. The reversal of 28749690 is 9694782.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 27154521 + 1595169 = 5211^2 + 1263^2 .

It is a super-2 number, since 2×28749690² = 1653089350192200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 159631 + ... + 159810.

Almost surely, 2^28749690 is an apocalyptic number.

28749690 is an abundant number, since it is smaller than the sum of its proper divisors (45999738).

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

28749690 is a wasteful number, since it uses less digits than its factorization.

28749690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319454 (or 319451 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 28749690 is about 5361.8737396548. The cubic root of 28749690 is about 306.3451826868.

The spelling of 28749690 in words is "twenty-eight million, seven hundred forty-nine thousand, six hundred ninety".