221100993 has 12 divisors (see below), whose sum is σ = 321025380. Its totient is φ = 146635776.

The previous prime is 221100989. The next prime is 221101007. The reversal of 221100993 is 399001122.

It can be written as a sum of positive squares in 2 ways, for example, as 38526849 + 182574144 = 6207^2 + 13512^2 .

It is not a de Polignac number, because 221100993 - 2² = 221100989 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221100953) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 61908 + ... + 65381.

It is an arithmetic number, because the mean of its divisors is an integer number (26752115).

Almost surely, 2^221100993 is an apocalyptic number.

It is an amenable number.

221100993 is a deficient number, since it is larger than the sum of its proper divisors (99924387).

221100993 is a wasteful number, since it uses less digits than its factorization.

221100993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127488 (or 127485 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 221100993 is about 14869.4651215166. The cubic root of 221100993 is about 604.6864418025.

The spelling of 221100993 in words is "two hundred twenty-one million, one hundred thousand, nine hundred ninety-three".