641887999901 has 2 divisors, whose sum is σ = 641887999902. Its totient is φ = 641887999900.

The previous prime is 641887999871. The next prime is 641887999933. The reversal of 641887999901 is 109999788146.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 533850883801 + 108037116100 = 730651^2 + 328690^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-641887999901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (641887999981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320943999950 + 320943999951.

It is an arithmetic number, because the mean of its divisors is an integer number (320943999951).

Almost surely, 2^641887999901 is an apocalyptic number.

It is an amenable number.

641887999901 is a deficient number, since it is larger than the sum of its proper divisors (1).

641887999901 is an equidigital number, since it uses as much as digits as its factorization.

641887999901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 70543872, while the sum is 71.

The spelling of 641887999901 in words is "six hundred forty-one billion, eight hundred eighty-seven million, nine hundred ninety-nine thousand, nine hundred one".