641547638 has 4 divisors (see below), whose sum is σ = 962321460. Its totient is φ = 320773818.

The previous prime is 641547617. The next prime is 641547707. The reversal of 641547638 is 836745146.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160386908 + ... + 160386911.

It is an arithmetic number, because the mean of its divisors is an integer number (240580365).

Almost surely, 2^641547638 is an apocalyptic number.

641547638 is a deficient number, since it is larger than the sum of its proper divisors (320773822).

641547638 is a wasteful number, since it uses less digits than its factorization.

641547638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320773821.

The product of its digits is 483840, while the sum is 44.

The square root of 641547638 is about 25328.7906935961. The cubic root of 641547638 is about 862.4679595463.

The spelling of 641547638 in words is "six hundred forty-one million, five hundred forty-seven thousand, six hundred thirty-eight".