641813651 has 2 divisors, whose sum is σ = 641813652. Its totient is φ = 641813650.

The previous prime is 641813639. The next prime is 641813693. The reversal of 641813651 is 156318146.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 641813651 - 2¹⁰ = 641812627 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (641813251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320906825 + 320906826.

It is an arithmetic number, because the mean of its divisors is an integer number (320906826).

Almost surely, 2^641813651 is an apocalyptic number.

641813651 is a deficient number, since it is larger than the sum of its proper divisors (1).

641813651 is an equidigital number, since it uses as much as digits as its factorization.

641813651 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17280, while the sum is 35.

The square root of 641813651 is about 25334.0413475624. The cubic root of 641813651 is about 862.5871484020.

The spelling of 641813651 in words is "six hundred forty-one million, eight hundred thirteen thousand, six hundred fifty-one".