641571863 has 2 divisors, whose sum is σ = 641571864. Its totient is φ = 641571862.

The previous prime is 641571809. The next prime is 641571899. The reversal of 641571863 is 368175146.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 641571863 - 2¹² = 641567767 is a prime.

It is a super-2 number, since 2×641571863² = 823228910786581538, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 641571863.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (641579863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320785931 + 320785932.

It is an arithmetic number, because the mean of its divisors is an integer number (320785932).

Almost surely, 2^641571863 is an apocalyptic number.

641571863 is a deficient number, since it is larger than the sum of its proper divisors (1).

641571863 is an equidigital number, since it uses as much as digits as its factorization.

641571863 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120960, while the sum is 41.

The square root of 641571863 is about 25329.2688998321. The cubic root of 641571863 is about 862.4788150786.

The spelling of 641571863 in words is "six hundred forty-one million, five hundred seventy-one thousand, eight hundred sixty-three".