66701557 has 16 divisors (see below), whose sum is σ = 77837760. Its totient is φ = 56593152.

The previous prime is 66701549. The next prime is 66701561. The reversal of 66701557 is 75510766.

It is a cyclic number.

It is not a de Polignac number, because 66701557 - 2³ = 66701549 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66701597) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5994 + ... + 13012.

It is an arithmetic number, because the mean of its divisors is an integer number (4864860).

Almost surely, 2^66701557 is an apocalyptic number.

It is an amenable number.

66701557 is a deficient number, since it is larger than the sum of its proper divisors (11136203).

66701557 is a wasteful number, since it uses less digits than its factorization.

66701557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7092.

The product of its (nonzero) digits is 44100, while the sum is 37.

The square root of 66701557 is about 8167.1021176425. The cubic root of 66701557 is about 405.5508573867.

The spelling of 66701557 in words is "sixty-six million, seven hundred one thousand, five hundred fifty-seven".