641531405 has 16 divisors (see below), whose sum is σ = 789919680. Its totient is φ = 499903488.

The previous prime is 641531399. The next prime is 641531413. The reversal of 641531405 is 504135146.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-641531405 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 77549 + ... + 85421.

It is an arithmetic number, because the mean of its divisors is an integer number (49369980).

Almost surely, 2^641531405 is an apocalyptic number.

It is an amenable number.

641531405 is a deficient number, since it is larger than the sum of its proper divisors (148388275).

641531405 is a wasteful number, since it uses less digits than its factorization.

641531405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8300.

The product of its (nonzero) digits is 7200, while the sum is 29.

The square root of 641531405 is about 25328.4702459505. The cubic root of 641531405 is about 862.4606851785.

The spelling of 641531405 in words is "six hundred forty-one million, five hundred thirty-one thousand, four hundred five".