66171690 has 96 divisors (see below), whose sum is σ = 193415040. Its totient is φ = 15573888.

The previous prime is 66171683. The next prime is 66171697. The reversal of 66171690 is 9617166.

It is an interprime number because it is at equal distance from previous prime (66171683) and next prime (66171697).

It is a super-2 number, since 2×66171690² = 8757385114912200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66171697) 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, 25681 + ... + 28139.

It is an arithmetic number, because the mean of its divisors is an integer number (2014740).

Almost surely, 2^66171690 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66171690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96707520).

66171690 is an abundant number, since it is smaller than the sum of its proper divisors (127243350).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66171690 is a wasteful number, since it uses less digits than its factorization.

66171690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2508 (or 2505 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 36.

The square root of 66171690 is about 8134.5983305877. The cubic root of 66171690 is about 404.4741231346.

The spelling of 66171690 in words is "sixty-six million, one hundred seventy-one thousand, six hundred ninety".