21816554035453 has 4 divisors (see below), whose sum is σ = 21817322604160. Its totient is φ = 21815785466748.

The previous prime is 21816554035433. The next prime is 21816554035469. The reversal of 21816554035453 is 35453045561812.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21816554035453 - 2⁹ = 21816554034941 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21816554035453.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21816554035433) 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, 384241773 + ... + 384298546.

It is an arithmetic number, because the mean of its divisors is an integer number (5454330651040).

Almost surely, 2^{21816554035453} is an apocalyptic number.

It is an amenable number.

21816554035453 is a deficient number, since it is larger than the sum of its proper divisors (768568707).

21816554035453 is an equidigital number, since it uses as much as digits as its factorization.

21816554035453 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 768568706.

The product of its (nonzero) digits is 8640000, while the sum is 52.

The spelling of 21816554035453 in words is "twenty-one trillion, eight hundred sixteen billion, five hundred fifty-four million, thirty-five thousand, four hundred fifty-three".