21455054221 has 8 divisors (see below), whose sum is σ = 22726895544. Its totient is φ = 20184299520.

The previous prime is 21455054183. The next prime is 21455054249. The reversal of 21455054221 is 12245055412.

It can be written as a sum of positive squares in 4 ways, for example, as 280730025 + 21174324196 = 16755^2 + 145514^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21455054221 - 2¹⁵ = 21455021453 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 (21455051221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 230820 + ... + 310141.

It is an arithmetic number, because the mean of its divisors is an integer number (2840861943).

Almost surely, 2^21455054221 is an apocalyptic number.

It is an amenable number.

21455054221 is a deficient number, since it is larger than the sum of its proper divisors (1271841323).

21455054221 is a wasteful number, since it uses less digits than its factorization.

21455054221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 543311.

The product of its (nonzero) digits is 16000, while the sum is 31.

The spelling of 21455054221 in words is "twenty-one billion, four hundred fifty-five million, fifty-four thousand, two hundred twenty-one".