66572720 has 20 divisors (see below), whose sum is σ = 154781760. Its totient is φ = 26629056.

The previous prime is 66572659. The next prime is 66572743. The reversal of 66572720 is 2727566.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (20).

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 416000 + ... + 416159.

It is an arithmetic number, because the mean of its divisors is an integer number (7739088).

Almost surely, 2^66572720 is an apocalyptic number.

It is an amenable number.

66572720 is an abundant number, since it is smaller than the sum of its proper divisors (88209040).

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

66572720 is a wasteful number, since it uses less digits than its factorization.

66572720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 832172 (or 832166 counting only the distinct ones).

The product of its (nonzero) digits is 35280, while the sum is 35.

The square root of 66572720 is about 8159.2107461445. The cubic root of 66572720 is about 405.2895759647.

The spelling of 66572720 in words is "sixty-six million, five hundred seventy-two thousand, seven hundred twenty".