641961264 has 80 divisors (see below), whose sum is σ = 1905036800. Its totient is φ = 182476800.

The previous prime is 641961263. The next prime is 641961269. The reversal of 641961264 is 462169146.

It is a super-2 number, since 2×641961264² = 824228528952955392, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (641961263) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 62064 + ... + 71664.

It is an arithmetic number, because the mean of its divisors is an integer number (23812960).

Almost surely, 2^641961264 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 641961264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (952518400).

641961264 is an abundant number, since it is smaller than the sum of its proper divisors (1263075536).

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

641961264 is a wasteful number, since it uses less digits than its factorization.

641961264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9818 (or 9812 counting only the distinct ones).

The product of its digits is 62208, while the sum is 39.

The square root of 641961264 is about 25336.9545131217. The cubic root of 641961264 is about 862.6532731596.

The spelling of 641961264 in words is "six hundred forty-one million, nine hundred sixty-one thousand, two hundred sixty-four".