21836716838551 has 4 divisors (see below), whose sum is σ = 21839263997112. Its totient is φ = 21834169679992.

The previous prime is 21836716838473. The next prime is 21836716838593. The reversal of 21836716838551 is 15583861763812.

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

It is a cyclic number.

It is not a de Polignac number, because 21836716838551 - 2⁷ = 21836716838423 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 (21836716878551) 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, 1273566421 + ... + 1273583566.

It is an arithmetic number, because the mean of its divisors is an integer number (5459815999278).

Almost surely, 2^{21836716838551} is an apocalyptic number.

21836716838551 is a deficient number, since it is larger than the sum of its proper divisors (2547158561).

21836716838551 is an equidigital number, since it uses as much as digits as its factorization.

21836716838551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2547158560.

The product of its digits is 58060800, while the sum is 64.

The spelling of 21836716838551 in words is "twenty-one trillion, eight hundred thirty-six billion, seven hundred sixteen million, eight hundred thirty-eight thousand, five hundred fifty-one".