64646172 has 72 divisors (see below), whose sum is σ = 175514976. Its totient is φ = 19989504.

The previous prime is 64646171. The next prime is 64646177. The reversal of 64646172 is 27164646.

64646172 is a `hidden beast` number, since 6 + 4 + 646 + 1 + 7 + 2 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64646171) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 43953 + ... + 45399.

It is an arithmetic number, because the mean of its divisors is an integer number (2437708).

Almost surely, 2^64646172 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64646172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (87757488).

64646172 is an abundant number, since it is smaller than the sum of its proper divisors (110868804).

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

64646172 is a wasteful number, since it uses less digits than its factorization.

64646172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1547 (or 1542 counting only the distinct ones).

The product of its digits is 48384, while the sum is 36.

The square root of 64646172 is about 8040.2843233309. The cubic root of 64646172 is about 401.3416863295.

The spelling of 64646172 in words is "sixty-four million, six hundred forty-six thousand, one hundred seventy-two".