63649581 has 8 divisors (see below), whose sum is σ = 89858304. Its totient is φ = 39936960.

The previous prime is 63649567. The next prime is 63649631. The reversal of 63649581 is 18594636.

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

It is not a de Polignac number, because 63649581 - 2⁶ = 63649517 is a prime.

It is a super-2 number, since 2×63649581² = 8102538322951122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63649501) 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, 623965 + ... + 624066.

It is an arithmetic number, because the mean of its divisors is an integer number (11232288).

Almost surely, 2^63649581 is an apocalyptic number.

It is an amenable number.

63649581 is a deficient number, since it is larger than the sum of its proper divisors (26208723).

63649581 is a wasteful number, since it uses less digits than its factorization.

63649581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1248051.

The product of its digits is 155520, while the sum is 42.

The square root of 63649581 is about 7978.0687512706. The cubic root of 63649581 is about 399.2686239544.

The spelling of 63649581 in words is "sixty-three million, six hundred forty-nine thousand, five hundred eighty-one".