28731530 has 16 divisors (see below), whose sum is σ = 54759240. Its totient is φ = 10816512.

The previous prime is 28731517. The next prime is 28731551. The reversal of 28731530 is 3513782.

It can be written as a sum of positive squares in 4 ways, for example, as 25110121 + 3621409 = 5011^2 + 1903^2 .

It is a super-2 number, since 2×28731530² = 1651001632281800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28731493 and 28731502.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84335 + ... + 84674.

Almost surely, 2^28731530 is an apocalyptic number.

28731530 is a deficient number, since it is larger than the sum of its proper divisors (26027710).

28731530 is a wasteful number, since it uses less digits than its factorization.

28731530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169033.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 28731530 is about 5360.1800342899. The cubic root of 28731530 is about 306.2806672052.

The spelling of 28731530 in words is "twenty-eight million, seven hundred thirty-one thousand, five hundred thirty".