221260166689 has 15 divisors (see below), whose sum is σ = 233731683393. Its totient is φ = 209454023772.

The previous prime is 221260166627. The next prime is 221260166707. The reversal of 221260166689 is 986661062122.

The square root of 221260166689 is 470383.

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

It is not a de Polignac number, because 221260166689 - 2¹¹ = 221260164641 is a prime.

It is a super-2 number, since 2×221260166689² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (221260166609) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 169807612 + ... + 169808914.

Almost surely, 2^221260166689 is an apocalyptic number.

221260166689 is the 470383-rd square number.

221260166689 is the 235192-nd centered octagonal number.

It is an amenable number.

221260166689 is a deficient number, since it is larger than the sum of its proper divisors (12471516704).

221260166689 is an frugal number, since it uses more digits than its factorization.

221260166689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2682 (or 1322 counting only the distinct ones).

The product of its (nonzero) digits is 746496, while the sum is 49.

Multiplying 221260166689 by its sum of digits (49), we get a square (10841748167761 = 3292681²).

The spelling of 221260166689 in words is "two hundred twenty-one billion, two hundred sixty million, one hundred sixty-six thousand, six hundred eighty-nine".