28661580 has 48 divisors (see below), whose sum is σ = 89171040. Its totient is φ = 7642944.

The previous prime is 28661579. The next prime is 28661593. The reversal of 28661580 is 8516682.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

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, 25999 + ... + 27078.

It is an arithmetic number, because the mean of its divisors is an integer number (1857730).

Almost surely, 2^28661580 is an apocalyptic number.

28661580 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28661580 is an abundant number, since it is smaller than the sum of its proper divisors (60509460).

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

28661580 is a wasteful number, since it uses less digits than its factorization.

28661580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53095 (or 53087 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 28661580 is about 5353.6510906110. The cubic root of 28661580 is about 306.0319074763.

It can be divided in two parts, 28661 and 580, that added together give a square (29241 = 171²).

The spelling of 28661580 in words is "twenty-eight million, six hundred sixty-one thousand, five hundred eighty".