63216568021 has 4 divisors (see below), whose sum is σ = 63217200492. Its totient is φ = 63215935552.

The previous prime is 63216568003. The next prime is 63216568133. The reversal of 63216568021 is 12086561236.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 30306979921 + 32909588100 = 174089^2 + 181410^2 .

It is a cyclic number.

It is not a de Polignac number, because 63216568021 - 2¹⁷ = 63216436949 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63216563021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 129586 + ... + 378451.

It is an arithmetic number, because the mean of its divisors is an integer number (15804300123).

Almost surely, 2^63216568021 is an apocalyptic number.

It is an amenable number.

63216568021 is a deficient number, since it is larger than the sum of its proper divisors (632471).

63216568021 is a wasteful number, since it uses less digits than its factorization.

63216568021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 632470.

The product of its (nonzero) digits is 103680, while the sum is 40.

The spelling of 63216568021 in words is "sixty-three billion, two hundred sixteen million, five hundred sixty-eight thousand, twenty-one".