28732440 has 64 divisors (see below), whose sum is σ = 94037760. Its totient is φ = 6965120.

The previous prime is 28732439. The next prime is 28732477. The reversal of 28732440 is 4423782.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 28732398 and 28732407.

It is a congruent number.

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, 9564 + ... + 12203.

It is an arithmetic number, because the mean of its divisors is an integer number (1469340).

Almost surely, 2^28732440 is an apocalyptic number.

28732440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28732440 is an abundant number, since it is smaller than the sum of its proper divisors (65305320).

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

28732440 is a wasteful number, since it uses less digits than its factorization.

28732440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21792 (or 21788 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 30.

The square root of 28732440 is about 5360.2649188263. The cubic root of 28732440 is about 306.2839007314.

The spelling of 28732440 in words is "twenty-eight million, seven hundred thirty-two thousand, four hundred forty".