641261244 has 48 divisors (see below), whose sum is σ = 1623726720. Its totient is φ = 195798720.

The previous prime is 641261239. The next prime is 641261251. The reversal of 641261244 is 442162146.

It is a happy number.

It is a super-2 number, since 2×641261244² = 822431966112855072, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4747 + ... + 36125.

It is an arithmetic number, because the mean of its divisors is an integer number (33827640).

Almost surely, 2^641261244 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 641261244, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (811863360).

641261244 is an abundant number, since it is smaller than the sum of its proper divisors (982465476).

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

641261244 is a wasteful number, since it uses less digits than its factorization.

641261244 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31530 (or 31528 counting only the distinct ones).

The product of its digits is 9216, while the sum is 30.

The square root of 641261244 is about 25323.1365355874. The cubic root of 641261244 is about 862.3396020149.

The spelling of 641261244 in words is "six hundred forty-one million, two hundred sixty-one thousand, two hundred forty-four".