63635612121 has 21 divisors (see below), whose sum is σ = 95419985349. Its totient is φ = 42419200716.

The previous prime is 63635612119. The next prime is 63635612149. The reversal of 63635612121 is 12121653636.

The square root of 63635612121 is 252261.

It is a perfect power (a square), and thus also a powerful number.

63635612121 is a `hidden beast` number, since 6 + 3 + 6 + 35 + 612 + 1 + 2 + 1 = 666.

It is not a de Polignac number, because 63635612121 - 2¹ = 63635612119 is a prime.

It is a super-2 number, since 2×63635612121² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (63635612191) by changing a digit.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 6806376 + ... + 6815718.

Almost surely, 2^63635612121 is an apocalyptic number.

63635612121 is the 252261-st square number.

63635612121 is the 126131-st centered octagonal number.

It is an amenable number.

63635612121 is a deficient number, since it is larger than the sum of its proper divisors (31784373228).

63635612121 is an frugal number, since it uses more digits than its factorization.

63635612121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18704 (or 9346 counting only the distinct ones).

The product of its digits is 38880, while the sum is 36.

Multiplying 63635612121 by its sum of digits (36), we get a square (2290882036356 = 1513566²).

The spelling of 63635612121 in words is "sixty-three billion, six hundred thirty-five million, six hundred twelve thousand, one hundred twenty-one".