66865905 has 40 divisors (see below), whose sum is σ = 121061952. Its totient is φ = 35305632.

The previous prime is 66865901. The next prime is 66865907. The reversal of 66865905 is 50956866.

It is not a de Polignac number, because 66865905 - 2² = 66865901 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (66865901) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 42564 + ... + 44106.

Almost surely, 2^66865905 is an apocalyptic number.

It is an amenable number.

66865905 is a deficient number, since it is larger than the sum of its proper divisors (54196047).

66865905 is a wasteful number, since it uses less digits than its factorization.

66865905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1667 (or 1658 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 45.

The square root of 66865905 is about 8177.1575134640. The cubic root of 66865905 is about 405.8836672369.

The spelling of 66865905 in words is "sixty-six million, eight hundred sixty-five thousand, nine hundred five".