221082373207921 has 9 divisors (see below), whose sum is σ = 223386527145099. Its totient is φ = 218801746075584.

The previous prime is 221082373207919. The next prime is 221082373207933. The reversal of 221082373207921 is 129702373280122.

The square root of 221082373207921 is 14868839.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 99274420959025 + 121807952248896 = 9963655^2 + 11036664^2 .

It is not a de Polignac number, because 221082373207921 - 2¹ = 221082373207919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221082373207901) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1442200740 + ... + 1442354026.

Almost surely, 2^{221082373207921} is an apocalyptic number.

221082373207921 is the 14868839-th square number.

221082373207921 is the 7434420-th centered octagonal number.

It is an amenable number.

221082373207921 is a deficient number, since it is larger than the sum of its proper divisors (2304153937178).

221082373207921 is an frugal number, since it uses more digits than its factorization.

221082373207921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 306768 (or 153384 counting only the distinct ones).

The product of its (nonzero) digits is 1016064, while the sum is 49.

The spelling of 221082373207921 in words is "two hundred twenty-one trillion, eighty-two billion, three hundred seventy-three million, two hundred seven thousand, nine hundred twenty-one".