221829621478172 has 6 divisors (see below), whose sum is σ = 388201837586808. Its totient is φ = 110914810739084.

The previous prime is 221829621478169. The next prime is 221829621478187. The reversal of 221829621478172 is 271874126928122.

It is a super-3 number, since 3×221829621478172³ (a number of 44 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27728702684768 + ... + 27728702684775.

It is an arithmetic number, because the mean of its divisors is an integer number (64700306264468).

Almost surely, 2^{221829621478172} is an apocalyptic number.

It is an amenable number.

221829621478172 is a deficient number, since it is larger than the sum of its proper divisors (166372216108636).

221829621478172 is a wasteful number, since it uses less digits than its factorization.

221829621478172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55457405369547 (or 55457405369545 counting only the distinct ones).

The product of its digits is 21676032, while the sum is 62.

The spelling of 221829621478172 in words is "two hundred twenty-one trillion, eight hundred twenty-nine billion, six hundred twenty-one million, four hundred seventy-eight thousand, one hundred seventy-two".