63981313561 has 8 divisors (see below), whose sum is σ = 70266240000. Its totient is φ = 57774461040.

The previous prime is 63981313547. The next prime is 63981313579. The reversal of 63981313561 is 16531318936.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 63981313561 - 2⁷ = 63981313433 is a prime.

It is not an unprimeable number, because it can be changed into a prime (63981313541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19516761 + ... + 19520038.

It is an arithmetic number, because the mean of its divisors is an integer number (8783280000).

Almost surely, 2^63981313561 is an apocalyptic number.

It is an amenable number.

63981313561 is a deficient number, since it is larger than the sum of its proper divisors (6284926439).

63981313561 is a wasteful number, since it uses less digits than its factorization.

63981313561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39036959.

The product of its digits is 349920, while the sum is 46.

The spelling of 63981313561 in words is "sixty-three billion, nine hundred eighty-one million, three hundred thirteen thousand, five hundred sixty-one".