63949581 has 12 divisors (see below), whose sum is σ = 95793152. Its totient is φ = 42632892.

The previous prime is 63949577. The next prime is 63949583. The reversal of 63949581 is 18594936.

It is a happy number.

63949581 is a `hidden beast` number, since 63 + 9 + 4 + 9 + 581 = 666.

It is not a de Polignac number, because 63949581 - 2² = 63949577 is a prime.

It is a super-2 number, since 2×63949581² = 8179097820151122, which 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 (63949583) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 131341 + ... + 131826.

Almost surely, 2^63949581 is an apocalyptic number.

It is an amenable number.

63949581 is a deficient number, since it is larger than the sum of its proper divisors (31843571).

63949581 is an equidigital number, since it uses as much as digits as its factorization.

63949581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 263182 (or 263170 counting only the distinct ones).

The product of its digits is 233280, while the sum is 45.

The square root of 63949581 is about 7996.8481916315. The cubic root of 63949581 is about 399.8949328213.

The spelling of 63949581 in words is "sixty-three million, nine hundred forty-nine thousand, five hundred eighty-one".