643416264 has 64 divisors (see below), whose sum is σ = 1798070400. Its totient is φ = 213175872.

The previous prime is 643416251. The next prime is 643416281. The reversal of 643416264 is 462614346.

643416264 is a `hidden beast` number, since 6 + 434 + 162 + 64 = 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 an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27154 + ... + 44990.

It is an arithmetic number, because the mean of its divisors is an integer number (28094850).

Almost surely, 2^643416264 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 643416264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (899035200).

643416264 is an abundant number, since it is smaller than the sum of its proper divisors (1154654136).

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

643416264 is a wasteful number, since it uses less digits than its factorization.

643416264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18019 (or 18009 counting only the distinct ones).

The product of its digits is 82944, while the sum is 36.

The square root of 643416264 is about 25365.6512630762. The cubic root of 643416264 is about 863.3045136132.

The spelling of 643416264 in words is "six hundred forty-three million, four hundred sixteen thousand, two hundred sixty-four".