641427776 has 84 divisors (see below), whose sum is σ = 1413371316. Its totient is φ = 288583680.

The previous prime is 641427767. The next prime is 641427779. The reversal of 641427776 is 677724146.

It can be written as a sum of positive squares in 2 ways, for example, as 315986176 + 325441600 = 17776^2 + 18040^2 .

It is a super-2 number, since 2×641427776² = 822859183648612352, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641427779) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 874706 + ... + 875438.

It is an arithmetic number, because the mean of its divisors is an integer number (16825849).

Almost surely, 2^641427776 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 641427776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (706685658).

641427776 is an abundant number, since it is smaller than the sum of its proper divisors (771943540).

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

641427776 is a wasteful number, since it uses less digits than its factorization.

641427776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 880 (or 859 counting only the distinct ones).

The product of its digits is 395136, while the sum is 44.

The square root of 641427776 is about 25326.4244614197. The cubic root of 641427776 is about 862.4142438297.

The spelling of 641427776 in words is "six hundred forty-one million, four hundred twenty-seven thousand, seven hundred seventy-six".