63842336581 has 4 divisors (see below), whose sum is σ = 64265133664. Its totient is φ = 63419539500.

The previous prime is 63842336573. The next prime is 63842336599. The reversal of 63842336581 is 18563324836.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 63842336581 - 2³ = 63842336573 is a prime.

It is a super-2 number, since 2×63842336581² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63842336521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 211398315 + ... + 211398616.

It is an arithmetic number, because the mean of its divisors is an integer number (16066283416).

Almost surely, 2^63842336581 is an apocalyptic number.

It is an amenable number.

63842336581 is a deficient number, since it is larger than the sum of its proper divisors (422797083).

63842336581 is a wasteful number, since it uses less digits than its factorization.

63842336581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 422797082.

The product of its digits is 2488320, while the sum is 49.

The spelling of 63842336581 in words is "sixty-three billion, eight hundred forty-two million, three hundred thirty-six thousand, five hundred eighty-one".