21424800664221 has 32 divisors (see below), whose sum is σ = 30894071390208. Its totient is φ = 13155395331840.

The previous prime is 21424800664193. The next prime is 21424800664243. The reversal of 21424800664221 is 12246600842412.

21424800664221 = T₉₅₄₈₀₃ + T₉₅₄₈₀₄ + ... + T₉₅₄₈₄₉.

It is not a de Polignac number, because 21424800664221 - 2⁷ = 21424800664093 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21424800664271) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19383736 + ... + 20459198.

It is an arithmetic number, because the mean of its divisors is an integer number (965439730944).

Almost surely, 2^{21424800664221} is an apocalyptic number.

It is an amenable number.

21424800664221 is a deficient number, since it is larger than the sum of its proper divisors (9469270725987).

21424800664221 is a wasteful number, since it uses less digits than its factorization.

21424800664221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1083841.

The product of its (nonzero) digits is 294912, while the sum is 42.

The spelling of 21424800664221 in words is "twenty-one trillion, four hundred twenty-four billion, eight hundred million, six hundred sixty-four thousand, two hundred twenty-one".