664811712 has 140 divisors (see below), whose sum is σ = 1982343000. Its totient is φ = 220299264.

The previous prime is 664811699. The next prime is 664811717. The reversal of 664811712 is 217118466.

It is a happy number.

664811712 is a `hidden beast` number, since 6 + 6 + 481 + 171 + 2 = 666.

It is a super-2 number, since 2×664811712² = 883949224824741888, which contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (664811717) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1332039 + ... + 1332537.

Almost surely, 2^664811712 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 664811712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (991171500).

664811712 is an abundant number, since it is smaller than the sum of its proper divisors (1317531288).

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

664811712 is a wasteful number, since it uses less digits than its factorization.

664811712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 780 (or 761 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 664811712 is about 25783.9429102688. The cubic root of 664811712 is about 872.7694860263.

The spelling of 664811712 in words is "six hundred sixty-four million, eight hundred eleven thousand, seven hundred twelve".