63645561 has 48 divisors (see below), whose sum is σ = 111355200. Its totient is φ = 35816256.

The previous prime is 63645559. The next prime is 63645583. The reversal of 63645561 is 16554636.

63645561 is a `hidden beast` number, since 6 + 3 + 645 + 5 + 6 + 1 = 666.

It is not a de Polignac number, because 63645561 - 2¹ = 63645559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (63645521) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 96250 + ... + 96908.

It is an arithmetic number, because the mean of its divisors is an integer number (2319900).

Almost surely, 2^63645561 is an apocalyptic number.

It is an amenable number.

63645561 is a deficient number, since it is larger than the sum of its proper divisors (47709639).

63645561 is a wasteful number, since it uses less digits than its factorization.

63645561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 755 (or 742 counting only the distinct ones).

The product of its digits is 64800, while the sum is 36.

The square root of 63645561 is about 7977.8168066207. The cubic root of 63645561 is about 399.2602180669.

The spelling of 63645561 in words is "sixty-three million, six hundred forty-five thousand, five hundred sixty-one".