641016881 has 4 divisors (see below), whose sum is σ = 643699200. Its totient is φ = 638334564.

The previous prime is 641016839. The next prime is 641016913. The reversal of 641016881 is 188610146.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-641016881 is a prime.

It is a super-2 number, since 2×641016881² = 821805283453936322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (641016581) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1340801 + ... + 1341278.

It is an arithmetic number, because the mean of its divisors is an integer number (160924800).

Almost surely, 2^641016881 is an apocalyptic number.

It is an amenable number.

641016881 is a deficient number, since it is larger than the sum of its proper divisors (2682319).

641016881 is a wasteful number, since it uses less digits than its factorization.

641016881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2682318.

The product of its (nonzero) digits is 9216, while the sum is 35.

The square root of 641016881 is about 25318.3111798556. The cubic root of 641016881 is about 862.2300519335.

The spelling of 641016881 in words is "six hundred forty-one million, sixteen thousand, eight hundred eighty-one".