66171963 has 16 divisors (see below), whose sum is σ = 103654656. Its totient is φ = 37019040.

The previous prime is 66171961. The next prime is 66171977. The reversal of 66171963 is 36917166.

It is not a de Polignac number, because 66171963 - 2¹ = 66171961 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (66171961) 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, 76695 + ... + 77552.

It is an arithmetic number, because the mean of its divisors is an integer number (6478416).

Almost surely, 2^66171963 is an apocalyptic number.

66171963 is a deficient number, since it is larger than the sum of its proper divisors (37482693).

66171963 is a wasteful number, since it uses less digits than its factorization.

66171963 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154274.

The product of its digits is 40824, while the sum is 39.

The square root of 66171963 is about 8134.6151107474. The cubic root of 66171963 is about 404.4746793709.

The spelling of 66171963 in words is "sixty-six million, one hundred seventy-one thousand, nine hundred sixty-three".