66996657 has 48 divisors (see below), whose sum is σ = 120032640. Its totient is φ = 35064576.

The previous prime is 66996653. The next prime is 66996689. The reversal of 66996657 is 75669966.

It is not a de Polignac number, because 66996657 - 2² = 66996653 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66996653) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 146373 + ... + 146829.

It is an arithmetic number, because the mean of its divisors is an integer number (2500680).

Almost surely, 2^66996657 is an apocalyptic number.

It is an amenable number.

66996657 is a deficient number, since it is larger than the sum of its proper divisors (53035983).

66996657 is a wasteful number, since it uses less digits than its factorization.

66996657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 662 (or 659 counting only the distinct ones).

The product of its digits is 3674160, while the sum is 54.

The square root of 66996657 is about 8185.1485630989. The cubic root of 66996657 is about 406.1480548301.

The spelling of 66996657 in words is "sixty-six million, nine hundred ninety-six thousand, six hundred fifty-seven".