63661507538 has 4 divisors (see below), whose sum is σ = 95492261310. Its totient is φ = 31830753768.

The previous prime is 63661507519. The next prime is 63661507561. The reversal of 63661507538 is 83570516636.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 44374686409 + 19286821129 = 210653^2 + 138877^2 .

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15915376883 + ... + 15915376886.

Almost surely, 2^63661507538 is an apocalyptic number.

63661507538 is a deficient number, since it is larger than the sum of its proper divisors (31830753772).

63661507538 is a wasteful number, since it uses less digits than its factorization.

63661507538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31830753771.

The product of its (nonzero) digits is 2721600, while the sum is 50.

The spelling of 63661507538 in words is "sixty-three billion, six hundred sixty-one million, five hundred seven thousand, five hundred thirty-eight".