641564889 has 24 divisors (see below), whose sum is σ = 996035328. Its totient is φ = 366256800.

The previous prime is 641564881. The next prime is 641564893. The reversal of 641564889 is 988465146.

It is not a de Polignac number, because 641564889 - 2³ = 641564881 is a prime.

It is not an unprimeable number, because it can be changed into a prime (641564881) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 285679 + ... + 287915.

It is an arithmetic number, because the mean of its divisors is an integer number (41501472).

Almost surely, 2^641564889 is an apocalyptic number.

It is an amenable number.

641564889 is a deficient number, since it is larger than the sum of its proper divisors (354470439).

641564889 is a wasteful number, since it uses less digits than its factorization.

641564889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4205 (or 4198 counting only the distinct ones).

The product of its digits is 1658880, while the sum is 51.

The square root of 641564889 is about 25329.1312326341. The cubic root of 641564889 is about 862.4756899680.

The spelling of 641564889 in words is "six hundred forty-one million, five hundred sixty-four thousand, eight hundred eighty-nine".