641161663 has 4 divisors (see below), whose sum is σ = 642159448. Its totient is φ = 640163880.

The previous prime is 641161657. The next prime is 641161699. The reversal of 641161663 is 366161146.

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

It is a cyclic number.

It is not a de Polignac number, because 641161663 - 2¹⁷ = 641030591 is a prime.

It is a super-2 number, since 2×641161663² = 822176556201851138, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641161603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 497928 + ... + 499213.

It is an arithmetic number, because the mean of its divisors is an integer number (160539862).

Almost surely, 2^641161663 is an apocalyptic number.

641161663 is a deficient number, since it is larger than the sum of its proper divisors (997785).

641161663 is an equidigital number, since it uses as much as digits as its factorization.

641161663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 997784.

The product of its digits is 15552, while the sum is 34.

The square root of 641161663 is about 25321.1702533670. The cubic root of 641161663 is about 862.2949623374.

The spelling of 641161663 in words is "six hundred forty-one million, one hundred sixty-one thousand, six hundred sixty-three".