664127136 has 144 divisors (see below), whose sum is σ = 1978179840. Its totient is φ = 211092480.

The previous prime is 664127129. The next prime is 664127141. The reversal of 664127136 is 631721466.

It is a happy number.

664127136 is a `hidden beast` number, since 6 + 641 + 2 + 7 + 1 + 3 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

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

It is a self number, because there is not a number n which added to its sum of digits gives 664127136.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 651235 + ... + 652253.

It is an arithmetic number, because the mean of its divisors is an integer number (13737360).

Almost surely, 2^664127136 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 664127136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (989089920).

664127136 is an abundant number, since it is smaller than the sum of its proper divisors (1314052704).

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

664127136 is a wasteful number, since it uses less digits than its factorization.

664127136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1139 (or 1128 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 664127136 is about 25770.6642522074. The cubic root of 664127136 is about 872.4698110807.

The spelling of 664127136 in words is "six hundred sixty-four million, one hundred twenty-seven thousand, one hundred thirty-six".