66905957 has 8 divisors (see below), whose sum is σ = 68448000. Its totient is φ = 65368944.

The previous prime is 66905947. The next prime is 66905977. The reversal of 66905957 is 75950966.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66905957 - 2⁸ = 66905701 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (47).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66905947) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42419 + ... + 43967.

It is an arithmetic number, because the mean of its divisors is an integer number (8556000).

Almost surely, 2^66905957 is an apocalyptic number.

It is an amenable number.

66905957 is a deficient number, since it is larger than the sum of its proper divisors (1542043).

66905957 is a wasteful number, since it uses less digits than its factorization.

66905957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2515.

The product of its (nonzero) digits is 510300, while the sum is 47.

The square root of 66905957 is about 8179.6061641133. The cubic root of 66905957 is about 405.9646911305.

The spelling of 66905957 in words is "sixty-six million, nine hundred five thousand, nine hundred fifty-seven".