16453636021 has 4 divisors (see below), whose sum is σ = 16573735692. Its totient is φ = 16333536352.

The previous prime is 16453636013. The next prime is 16453636049. The reversal of 16453636021 is 12063635461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12063635461 = 31 ⋅389149531.

It can be written as a sum of positive squares in 2 ways, for example, as 13528016100 + 2925619921 = 116310^2 + 54089^2 .

It is a cyclic number.

It is not a de Polignac number, because 16453636021 - 2³ = 16453636013 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 (16453636921) 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, 60049630 + ... + 60049903.

It is an arithmetic number, because the mean of its divisors is an integer number (4143433923).

Almost surely, 2^16453636021 is an apocalyptic number.

It is an amenable number.

16453636021 is a deficient number, since it is larger than the sum of its proper divisors (120099671).

16453636021 is a wasteful number, since it uses less digits than its factorization.

16453636021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120099670.

The product of its (nonzero) digits is 77760, while the sum is 37.

The spelling of 16453636021 in words is "sixteen billion, four hundred fifty-three million, six hundred thirty-six thousand, twenty-one".