641309961 has 8 divisors (see below), whose sum is σ = 856212544. Its totient is φ = 426973680.

The previous prime is 641309959. The next prime is 641310001. The reversal of 641309961 is 169903146.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 641309961 - 2¹ = 641309959 is a prime.

It is a super-2 number, since 2×641309961² = 822556932155643042, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (641309761) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 138925 + ... + 143466.

It is an arithmetic number, because the mean of its divisors is an integer number (107026568).

Almost surely, 2^641309961 is an apocalyptic number.

It is an amenable number.

641309961 is a deficient number, since it is larger than the sum of its proper divisors (214902583).

641309961 is a wasteful number, since it uses less digits than its factorization.

641309961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283151.

The product of its (nonzero) digits is 34992, while the sum is 39.

The square root of 641309961 is about 25324.0984242283. The cubic root of 641309961 is about 862.3614389469.

The spelling of 641309961 in words is "six hundred forty-one million, three hundred nine thousand, nine hundred sixty-one".