66161664 has 88 divisors (see below), whose sum is σ = 196020720. Its totient is φ = 22044672.

The previous prime is 66161633. The next prime is 66161687. The reversal of 66161664 is 46616166.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a zygodrome in base 2.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26452 + ... + 28844.

Almost surely, 2^66161664 is an apocalyptic number.

66161664 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66161664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98010360).

66161664 is an abundant number, since it is smaller than the sum of its proper divisors (129859056).

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

66161664 is a wasteful number, since it uses less digits than its factorization.

66161664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2422 (or 2398 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 66161664 is about 8133.9820506318. The cubic root of 66161664 is about 404.4536941446.

The spelling of 66161664 in words is "sixty-six million, one hundred sixty-one thousand, six hundred sixty-four".