1664172 has 48 divisors (see below), whose sum is σ = 4547200. Its totient is φ = 524880.

The previous prime is 1664123. The next prime is 1664227. The reversal of 1664172 is 2714661.

1664172 is a `hidden beast` number, since 16 + 641 + 7 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1647 + ... + 2457.

2^1664172 is an apocalyptic number.

1664172 is a gapful number since it is divisible by the number (12) 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 1664172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2273600).

1664172 is an abundant number, since it is smaller than the sum of its proper divisors (2883028).

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

1664172 is a wasteful number, since it uses less digits than its factorization.

1664172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 843 (or 835 counting only the distinct ones).

The product of its digits is 2016, while the sum is 27.

The square root of 1664172 is about 1290.0279066749. The cubic root of 1664172 is about 118.5039255229.

The spelling of 1664172 in words is "one million, six hundred sixty-four thousand, one hundred seventy-two".