63985581 has 24 divisors (see below), whose sum is σ = 104083200. Its totient is φ = 37526400.

The previous prime is 63985561. The next prime is 63985583. The reversal of 63985581 is 18558936.

63985581 is a `hidden beast` number, since 6 + 3 + 98 + 558 + 1 = 666.

It is not a de Polignac number, because 63985581 - 2⁹ = 63985069 is a prime.

It is a super-2 number, since 2×63985581² = 8188309151815122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63985583) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7356 + ... + 13493.

It is an arithmetic number, because the mean of its divisors is an integer number (4336800).

Almost surely, 2^63985581 is an apocalyptic number.

It is an amenable number.

63985581 is a deficient number, since it is larger than the sum of its proper divisors (40097619).

63985581 is a wasteful number, since it uses less digits than its factorization.

63985581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20897 (or 20894 counting only the distinct ones).

The product of its digits is 259200, while the sum is 45.

The square root of 63985581 is about 7999.0987617356. The cubic root of 63985581 is about 399.9699581604.

It can be divided in two parts, 639855 and 81, that added together give a palindrome (639936).

The spelling of 63985581 in words is "sixty-three million, nine hundred eighty-five thousand, five hundred eighty-one".