641428956 has 120 divisors (see below), whose sum is σ = 1925170016. Its totient is φ = 182424960.

The previous prime is 641428937. The next prime is 641428973. The reversal of 641428956 is 659824146.

It is a super-2 number, since 2×641428956² = 822862211190499872, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 627726 + ... + 628746.

Almost surely, 2^641428956 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 641428956, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (962585008).

641428956 is an abundant number, since it is smaller than the sum of its proper divisors (1283741060).

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

641428956 is a wasteful number, since it uses less digits than its factorization.

641428956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1321 (or 1310 counting only the distinct ones).

The product of its digits is 414720, while the sum is 45.

The square root of 641428956 is about 25326.4477572359. The cubic root of 641428956 is about 862.4147726750.

The spelling of 641428956 in words is "six hundred forty-one million, four hundred twenty-eight thousand, nine hundred fifty-six".