28781715 has 16 divisors (see below), whose sum is σ = 46309536. Its totient is φ = 15264000.

The previous prime is 28781707. The next prime is 28781723. The reversal of 28781715 is 51718782.

It is an interprime number because it is at equal distance from previous prime (28781707) and next prime (28781723).

It is not a de Polignac number, because 28781715 - 2³ = 28781707 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2586 + ... + 8015.

It is an arithmetic number, because the mean of its divisors is an integer number (2894346).

Almost surely, 2^28781715 is an apocalyptic number.

28781715 is a deficient number, since it is larger than the sum of its proper divisors (17527821).

28781715 is a wasteful number, since it uses less digits than its factorization.

28781715 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10790.

The product of its digits is 31360, while the sum is 39.

The square root of 28781715 is about 5364.8592712204. The cubic root of 28781715 is about 306.4588890019.

The spelling of 28781715 in words is "twenty-eight million, seven hundred eighty-one thousand, seven hundred fifteen".