641905394 has 16 divisors (see below), whose sum is σ = 1038258648. Its totient is φ = 295882752.

The previous prime is 641905349. The next prime is 641905403. The reversal of 641905394 is 493509146.

It can be written as a sum of positive squares in 4 ways, for example, as 614395369 + 27510025 = 24787^2 + 5245^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5234 + ... + 36210.

Almost surely, 2^641905394 is an apocalyptic number.

641905394 is a deficient number, since it is larger than the sum of its proper divisors (396353254).

641905394 is a wasteful number, since it uses less digits than its factorization.

641905394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31789.

The product of its (nonzero) digits is 116640, while the sum is 41.

The square root of 641905394 is about 25335.8519493622. The cubic root of 641905394 is about 862.6282468123.

The spelling of 641905394 in words is "six hundred forty-one million, nine hundred five thousand, three hundred ninety-four".