21890538670221 has 48 divisors (see below), whose sum is σ = 34085036224512. Its totient is φ = 13458015504000.

The previous prime is 21890538670141. The next prime is 21890538670223. The reversal of 21890538670221 is 12207683509812.

21890538670221 is a `hidden beast` number, since 2 + 1 + 89 + 0 + 538 + 6 + 7 + 0 + 2 + 21 = 666.

It is not a de Polignac number, because 21890538670221 - 2²¹ = 21890536573069 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21890538670223) 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 47 ways as a sum of consecutive naturals, for example, 1037406571 + ... + 1037427671.

It is an arithmetic number, because the mean of its divisors is an integer number (710104921344).

Almost surely, 2^{21890538670221} is an apocalyptic number.

It is an amenable number.

21890538670221 is a deficient number, since it is larger than the sum of its proper divisors (12194497554291).

21890538670221 is a wasteful number, since it uses less digits than its factorization.

21890538670221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29314 (or 29311 counting only the distinct ones).

The product of its (nonzero) digits is 2903040, while the sum is 54.

The spelling of 21890538670221 in words is "twenty-one trillion, eight hundred ninety billion, five hundred thirty-eight million, six hundred seventy thousand, two hundred twenty-one".