646612164 has 144 divisors (see below), whose sum is σ = 1831624704. Its totient is φ = 190699200.

The previous prime is 646612163. The next prime is 646612223. The reversal of 646612164 is 461216646.

646612164 is a `hidden beast` number, since 646 + 6 + 1 + 2 + 1 + 6 + 4 = 666.

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 not an unprimeable number, because it can be changed into a prime (646612163) 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 47 ways as a sum of consecutive naturals, for example, 3385309 + ... + 3385499.

It is an arithmetic number, because the mean of its divisors is an integer number (12719616).

Almost surely, 2^646612164 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 646612164, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (915812352).

646612164 is an abundant number, since it is smaller than the sum of its proper divisors (1185012540).

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

646612164 is a wasteful number, since it uses less digits than its factorization.

646612164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 398 (or 393 counting only the distinct ones).

The product of its digits is 41472, while the sum is 36.

The square root of 646612164 is about 25428.5698378812. The cubic root of 646612164 is about 864.7315210306.

The spelling of 646612164 in words is "six hundred forty-six million, six hundred twelve thousand, one hundred sixty-four".