28787013 has 6 divisors (see below), whose sum is σ = 41581254. Its totient is φ = 19191336.

The previous prime is 28786997. The next prime is 28787023. The reversal of 28787013 is 31078782.

It can be written as a sum of positive squares in only one way, i.e., 22867524 + 5919489 = 4782^2 + 2433^2 .

It is not a de Polignac number, because 28787013 - 2⁴ = 28786997 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28787023) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1599270 + ... + 1599287.

It is an arithmetic number, because the mean of its divisors is an integer number (6930209).

Almost surely, 2^28787013 is an apocalyptic number.

It is an amenable number.

28787013 is a deficient number, since it is larger than the sum of its proper divisors (12794241).

28787013 is a wasteful number, since it uses less digits than its factorization.

28787013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3198563 (or 3198560 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 28787013 is about 5365.3530172767. The cubic root of 28787013 is about 306.4776916755.

The spelling of 28787013 in words is "twenty-eight million, seven hundred eighty-seven thousand, thirteen".