641159891 has 16 divisors (see below), whose sum is σ = 682214400. Its totient is φ = 601302240.

The previous prime is 641159867. The next prime is 641159899. The reversal of 641159891 is 198951146.

It is a cyclic number.

It is not a de Polignac number, because 641159891 - 2¹⁴ = 641143507 is a prime.

It is a super-2 number, since 2×641159891² = 822172011654263762, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (641159899) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 323981 + ... + 325953.

It is an arithmetic number, because the mean of its divisors is an integer number (42638400).

Almost surely, 2^641159891 is an apocalyptic number.

641159891 is a deficient number, since it is larger than the sum of its proper divisors (41054509).

641159891 is a wasteful number, since it uses less digits than its factorization.

641159891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2266.

The product of its digits is 77760, while the sum is 44.

The square root of 641159891 is about 25321.1352628590. The cubic root of 641159891 is about 862.2941679522.

The spelling of 641159891 in words is "six hundred forty-one million, one hundred fifty-nine thousand, eight hundred ninety-one".