641373440 has 72 divisors (see below), whose sum is σ = 1550721480. Its totient is φ = 254140416.

The previous prime is 641373437. The next prime is 641373449. The reversal of 641373440 is 44373146.

It can be written as a sum of positive squares in 4 ways, for example, as 17572864 + 623800576 = 4192^2 + 24976^2 .

It is a super-2 number, since 2×641373440² = 822719779074867200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 641373397 and 641373406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641373449) 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 7 ways as a sum of consecutive naturals, for example, 137222 + ... + 141818.

Almost surely, 2^641373440 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 641373440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (775360740).

641373440 is an abundant number, since it is smaller than the sum of its proper divisors (909348040).

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

641373440 is a wasteful number, since it uses less digits than its factorization.

641373440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4727 (or 4713 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 32.

The square root of 641373440 is about 25325.3517250995. The cubic root of 641373440 is about 862.3898911458.

The spelling of 641373440 in words is "six hundred forty-one million, three hundred seventy-three thousand, four hundred forty".