636134354021 has 4 divisors (see below), whose sum is σ = 636151925772. Its totient is φ = 636116782272.

The previous prime is 636134354017. The next prime is 636134354027. The reversal of 636134354021 is 120453431636.

636134354021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 247894452100 + 388239901921 = 497890^2 + 623089^2 .

It is a cyclic number.

It is not a de Polignac number, because 636134354021 - 2² = 636134354017 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (636134354027) 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, 8731460 + ... + 8804013.

It is an arithmetic number, because the mean of its divisors is an integer number (159037981443).

Almost surely, 2^636134354021 is an apocalyptic number.

It is an amenable number.

636134354021 is a deficient number, since it is larger than the sum of its proper divisors (17571751).

636134354021 is a wasteful number, since it uses less digits than its factorization.

636134354021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17571750.

The product of its (nonzero) digits is 155520, while the sum is 38.

Adding to 636134354021 its reverse (120453431636), we get a palindrome (756587785657).

The spelling of 636134354021 in words is "six hundred thirty-six billion, one hundred thirty-four million, three hundred fifty-four thousand, twenty-one".