641427640 has 96 divisors (see below), whose sum is σ = 1702216080. Its totient is φ = 216857088.

The previous prime is 641427637. The next prime is 641427641. The reversal of 641427640 is 46724146.

641427640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×641427640² = 822858834711939200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 641427596 and 641427605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641427641) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 140839 + ... + 145321.

Almost surely, 2^641427640 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 641427640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (851108040).

641427640 is an abundant number, since it is smaller than the sum of its proper divisors (1060788440).

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

641427640 is a wasteful number, since it uses less digits than its factorization.

641427640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4581 (or 4570 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 34.

The square root of 641427640 is about 25326.4217764768. The cubic root of 641427640 is about 862.4141828780.

The spelling of 641427640 in words is "six hundred forty-one million, four hundred twenty-seven thousand, six hundred forty".