66572816 has 20 divisors (see below), whose sum is σ = 136572732. Its totient is φ = 31328256.

The previous prime is 66572813. The next prime is 66572887. The reversal of 66572816 is 61827566.

It can be written as a sum of positive squares in 2 ways, for example, as 39740416 + 26832400 = 6304^2 + 5180^2 .

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (66572813) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 122105 + ... + 122648.

Almost surely, 2^66572816 is an apocalyptic number.

It is an amenable number.

66572816 is an abundant number, since it is smaller than the sum of its proper divisors (69999916).

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

66572816 is a wasteful number, since it uses less digits than its factorization.

66572816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244778 (or 244772 counting only the distinct ones).

The product of its digits is 120960, while the sum is 41.

The square root of 66572816 is about 8159.2166290643. The cubic root of 66572816 is about 405.2897707781.

The spelling of 66572816 in words is "sixty-six million, five hundred seventy-two thousand, eight hundred sixteen".