28724751 has 24 divisors (see below), whose sum is σ = 47648640. Its totient is φ = 16491600.

The previous prime is 28724749. The next prime is 28724753. The reversal of 28724751 is 15742782.

It is an interprime number because it is at equal distance from previous prime (28724749) and next prime (28724753).

It is not a de Polignac number, because 28724751 - 2¹ = 28724749 is a prime.

It is a super-2 number, since 2×28724751² = 1650222640024002, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28724753) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5755 + ... + 9516.

It is an arithmetic number, because the mean of its divisors is an integer number (1985360).

Almost surely, 2^28724751 is an apocalyptic number.

28724751 is a deficient number, since it is larger than the sum of its proper divisors (18923889).

28724751 is a wasteful number, since it uses less digits than its factorization.

28724751 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15307 (or 15304 counting only the distinct ones).

The product of its digits is 31360, while the sum is 36.

The square root of 28724751 is about 5359.5476488226. The cubic root of 28724751 is about 306.2565770627.

The spelling of 28724751 in words is "twenty-eight million, seven hundred twenty-four thousand, seven hundred fifty-one".