641905540 has 48 divisors (see below), whose sum is σ = 1365154560. Its totient is φ = 253514240.

The previous prime is 641905529. The next prime is 641905541. The reversal of 641905540 is 45509146.

It is a junction number, because it is equal to n+sod(n) for n = 641905496 and 641905505.

It is not an unprimeable number, because it can be changed into a prime (641905541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 973731 + ... + 974389.

It is an arithmetic number, because the mean of its divisors is an integer number (28440720).

Almost surely, 2^641905540 is an apocalyptic number.

It is an amenable number.

641905540 is an abundant number, since it is smaller than the sum of its proper divisors (723249020).

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

641905540 is a wasteful number, since it uses less digits than its factorization.

641905540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1212 (or 1210 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 34.

The square root of 641905540 is about 25335.8548306545. The cubic root of 641905540 is about 862.6283122133.

The spelling of 641905540 in words is "six hundred forty-one million, nine hundred five thousand, five hundred forty".