63788993561 has 4 divisors (see below), whose sum is σ = 65513020452. Its totient is φ = 62064966672.

The previous prime is 63788993557. The next prime is 63788993579. The reversal of 63788993561 is 16539988736.

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

It can be written as a sum of positive squares in 2 ways, for example, as 26792779225 + 36996214336 = 163685^2 + 192344^2 .

It is a cyclic number.

It is not a de Polignac number, because 63788993561 - 2² = 63788993557 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (63788993161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 862013390 + ... + 862013463.

It is an arithmetic number, because the mean of its divisors is an integer number (16378255113).

Almost surely, 2^63788993561 is an apocalyptic number.

It is an amenable number.

63788993561 is a deficient number, since it is larger than the sum of its proper divisors (1724026891).

63788993561 is a wasteful number, since it uses less digits than its factorization.

63788993561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1724026890.

The product of its digits is 58786560, while the sum is 65.

The spelling of 63788993561 in words is "sixty-three billion, seven hundred eighty-eight million, nine hundred ninety-three thousand, five hundred sixty-one".