66814657 has 12 divisors (see below), whose sum is σ = 82686720. Its totient is φ = 52863408.

The previous prime is 66814651. The next prime is 66814661. The reversal of 66814657 is 75641866.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-66814657 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 (66814651) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 27057 + ... + 29422.

It is an arithmetic number, because the mean of its divisors is an integer number (6890560).

Almost surely, 2^66814657 is an apocalyptic number.

It is an amenable number.

66814657 is a deficient number, since it is larger than the sum of its proper divisors (15872063).

66814657 is a wasteful number, since it uses less digits than its factorization.

66814657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56512 (or 56499 counting only the distinct ones).

The product of its digits is 241920, while the sum is 43.

The square root of 66814657 is about 8174.0233055699. The cubic root of 66814657 is about 405.7799469999.

The spelling of 66814657 in words is "sixty-six million, eight hundred fourteen thousand, six hundred fifty-seven".