641091663 has 12 divisors (see below), whose sum is σ = 927474288. Its totient is φ = 426723840.

The previous prime is 641091631. The next prime is 641091667. The reversal of 641091663 is 366190146.

641091663 is a `hidden beast` number, since 641 + 0 + 9 + 1 + 6 + 6 + 3 = 666.

It is not a de Polignac number, because 641091663 - 2⁵ = 641091631 is a prime.

641091663 is a modest number, since divided by 91663 gives 641 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641091667) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 49795 + ... + 61332.

It is an arithmetic number, because the mean of its divisors is an integer number (77289524).

Almost surely, 2^641091663 is an apocalyptic number.

641091663 is a deficient number, since it is larger than the sum of its proper divisors (286382625).

641091663 is a wasteful number, since it uses less digits than its factorization.

641091663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111774 (or 111771 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The square root of 641091663 is about 25319.7879730459. The cubic root of 641091663 is about 862.2635803175.

The spelling of 641091663 in words is "six hundred forty-one million, ninety-one thousand, six hundred sixty-three".