641654381 has 2 divisors, whose sum is σ = 641654382. Its totient is φ = 641654380.

The previous prime is 641654371. The next prime is 641654393. The reversal of 641654381 is 183456146.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 540330025 + 101324356 = 23245^2 + 10066^2 .

It is a cyclic number.

It is not a de Polignac number, because 641654381 - 2¹⁰ = 641653357 is a prime.

It is a super-2 number, since 2×641654381² = 823440689312986322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (641654371) 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 as a sum of consecutive naturals, namely, 320827190 + 320827191.

It is an arithmetic number, because the mean of its divisors is an integer number (320827191).

Almost surely, 2^641654381 is an apocalyptic number.

It is an amenable number.

641654381 is a deficient number, since it is larger than the sum of its proper divisors (1).

641654381 is an equidigital number, since it uses as much as digits as its factorization.

641654381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 69120, while the sum is 38.

The square root of 641654381 is about 25330.8977535341. The cubic root of 641654381 is about 862.5157903991.

The spelling of 641654381 in words is "six hundred forty-one million, six hundred fifty-four thousand, three hundred eighty-one".