28720470 has 16 divisors (see below), whose sum is σ = 68929200. Its totient is φ = 7658784.

The previous prime is 28720453. The next prime is 28720487. The reversal of 28720470 is 7402782.

It is an interprime number because it is at equal distance from previous prime (28720453) and next prime (28720487).

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 957349 = 28720470 / (2 + 8 + 7 + 2 + 0 + 4 + 7 + 0).

It is a Curzon number.

It is a congruent number.

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, 478645 + ... + 478704.

It is an arithmetic number, because the mean of its divisors is an integer number (4308075).

Almost surely, 2^28720470 is an apocalyptic number.

28720470 is an abundant number, since it is smaller than the sum of its proper divisors (40208730).

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

28720470 is a wasteful number, since it uses less digits than its factorization.

28720470 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 957359.

The product of its (nonzero) digits is 6272, while the sum is 30.

The square root of 28720470 is about 5359.1482532208. The cubic root of 28720470 is about 306.2413619665.

The spelling of 28720470 in words is "twenty-eight million, seven hundred twenty thousand, four hundred seventy".