641705764 has 18 divisors (see below), whose sum is σ = 1306329990. Its totient is φ = 275016672.

The previous prime is 641705761. The next prime is 641705789. The reversal of 641705764 is 467507146.

It can be written as a sum of positive squares in only one way, i.e., 631516900 + 10188864 = 25130^2 + 3192^2 .

It is not an unprimeable number, because it can be changed into a prime (641705761) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1636809 + ... + 1637200.

Almost surely, 2^641705764 is an apocalyptic number.

It is an amenable number.

641705764 is an abundant number, since it is smaller than the sum of its proper divisors (664624226).

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

641705764 is a wasteful number, since it uses less digits than its factorization.

641705764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3274027 (or 3274018 counting only the distinct ones).

The product of its (nonzero) digits is 141120, while the sum is 40.

The square root of 641705764 is about 25331.9119688980. The cubic root of 641705764 is about 862.5388129002.

The spelling of 641705764 in words is "six hundred forty-one million, seven hundred five thousand, seven hundred sixty-four".