21455254211 has 4 divisors (see below), whose sum is σ = 21455925624. Its totient is φ = 21454582800.

The previous prime is 21455254207. The next prime is 21455254229. The reversal of 21455254211 is 11245255412.

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 21455254211 - 2² = 21455254207 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21455254111) 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, 285245 + ... + 352526.

It is an arithmetic number, because the mean of its divisors is an integer number (5363981406).

Almost surely, 2^21455254211 is an apocalyptic number.

21455254211 is a deficient number, since it is larger than the sum of its proper divisors (671413).

21455254211 is an equidigital number, since it uses as much as digits as its factorization.

21455254211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 671412.

The product of its digits is 16000, while the sum is 32.

The spelling of 21455254211 in words is "twenty-one billion, four hundred fifty-five million, two hundred fifty-four thousand, two hundred eleven".