641361721 has 64 divisors (see below), whose sum is σ = 892717056. Its totient is φ = 444787200.

The previous prime is 641361649. The next prime is 641361731. The reversal of 641361721 is 127163146.

It is not a de Polignac number, because 641361721 - 2⁹ = 641361209 is a prime.

It is a super-2 number, since 2×641361721² = 822689714328163682, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (641361731) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4895826 + ... + 4895956.

It is an arithmetic number, because the mean of its divisors is an integer number (13948704).

Almost surely, 2^641361721 is an apocalyptic number.

It is an amenable number.

641361721 is a deficient number, since it is larger than the sum of its proper divisors (251355335).

641361721 is a wasteful number, since it uses less digits than its factorization.

641361721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 302.

The product of its digits is 6048, while the sum is 31.

The square root of 641361721 is about 25325.1203550941. The cubic root of 641361721 is about 862.3846386631.

The spelling of 641361721 in words is "six hundred forty-one million, three hundred sixty-one thousand, seven hundred twenty-one".