66564729 has 24 divisors (see below), whose sum is σ = 119875392. Its totient is φ = 34578720.

The previous prime is 66564709. The next prime is 66564749. The reversal of 66564729 is 92746566.

66564729 is a `hidden beast` number, since 66 + 564 + 7 + 29 = 666.

It is an interprime number because it is at equal distance from previous prime (66564709) and next prime (66564749).

It is not a de Polignac number, because 66564729 - 2¹⁵ = 66531961 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66564709) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 47334 + ... + 48719.

It is an arithmetic number, because the mean of its divisors is an integer number (4994808).

Almost surely, 2^66564729 is an apocalyptic number.

It is an amenable number.

66564729 is a deficient number, since it is larger than the sum of its proper divisors (53310663).

66564729 is a wasteful number, since it uses less digits than its factorization.

66564729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96077 (or 96074 counting only the distinct ones).

The product of its digits is 544320, while the sum is 45.

The square root of 66564729 is about 8158.7210394767. The cubic root of 66564729 is about 405.2733591189.

It can be divided in two parts, 66564 and 729, that multiplied together give a square (48525156 = 6966²).

The spelling of 66564729 in words is "sixty-six million, five hundred sixty-four thousand, seven hundred twenty-nine".