21455450153551 has 4 divisors (see below), whose sum is σ = 21455473163152. Its totient is φ = 21455427143952.

The previous prime is 21455450153513. The next prime is 21455450153611. The reversal of 21455450153551 is 15535105455412.

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 21455450153551 - 2³⁵ = 21421090415183 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 (21455450150551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10044315 + ... + 11991628.

It is an arithmetic number, because the mean of its divisors is an integer number (5363868290788).

Almost surely, 2^{21455450153551} is an apocalyptic number.

21455450153551 is a deficient number, since it is larger than the sum of its proper divisors (23009601).

21455450153551 is an equidigital number, since it uses as much as digits as its factorization.

21455450153551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23009600.

The product of its (nonzero) digits is 1500000, while the sum is 46.

The spelling of 21455450153551 in words is "twenty-one trillion, four hundred fifty-five billion, four hundred fifty million, one hundred fifty-three thousand, five hundred fifty-one".