66164557 has 4 divisors (see below), whose sum is σ = 66373596. Its totient is φ = 65955520.

The previous prime is 66164543. The next prime is 66164569. The reversal of 66164557 is 75546166.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3896676 + 62267881 = 1974^2 + 7891^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66164557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66164257) 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, 104044 + ... + 104677.

It is an arithmetic number, because the mean of its divisors is an integer number (16593399).

Almost surely, 2^66164557 is an apocalyptic number.

It is an amenable number.

66164557 is a deficient number, since it is larger than the sum of its proper divisors (209039).

66164557 is a wasteful number, since it uses less digits than its factorization.

66164557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209038.

The product of its digits is 151200, while the sum is 40.

The square root of 66164557 is about 8134.1598828644. The cubic root of 66164557 is about 404.4595891368.

The spelling of 66164557 in words is "sixty-six million, one hundred sixty-four thousand, five hundred fifty-seven".