21621334062455 has 4 divisors (see below), whose sum is σ = 25945600874952. Its totient is φ = 17297067249960.

The previous prime is 21621334062371. The next prime is 21621334062487. The reversal of 21621334062455 is 55426043312612.

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

It is not a de Polignac number, because 21621334062455 - 2¹⁴ = 21621334046071 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2162133406241 + ... + 2162133406250.

It is an arithmetic number, because the mean of its divisors is an integer number (6486400218738).

Almost surely, 2^{21621334062455} is an apocalyptic number.

21621334062455 is a deficient number, since it is larger than the sum of its proper divisors (4324266812497).

21621334062455 is an equidigital number, since it uses as much as digits as its factorization.

21621334062455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4324266812496.

The product of its (nonzero) digits is 1036800, while the sum is 44.

The spelling of 21621334062455 in words is "twenty-one trillion, six hundred twenty-one billion, three hundred thirty-four million, sixty-two thousand, four hundred fifty-five".