66957985 has 16 divisors (see below), whose sum is σ = 87823872. Its totient is φ = 48787200.

The previous prime is 66957983. The next prime is 66958007. The reversal of 66957985 is 58975966.

It is a happy number.

It is not a de Polignac number, because 66957985 - 2¹ = 66957983 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66957983) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10071 + ... + 15340.

It is an arithmetic number, because the mean of its divisors is an integer number (5488992).

Almost surely, 2^66957985 is an apocalyptic number.

It is an amenable number.

66957985 is a deficient number, since it is larger than the sum of its proper divisors (20865887).

66957985 is a wasteful number, since it uses less digits than its factorization.

66957985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25464.

The product of its digits is 4082400, while the sum is 55.

The square root of 66957985 is about 8182.7858947916. The cubic root of 66957985 is about 406.0698938127.

The spelling of 66957985 in words is "sixty-six million, nine hundred fifty-seven thousand, nine hundred eighty-five".