221045823 has 6 divisors (see below), whose sum is σ = 319288424. Its totient is φ = 147363876.

The previous prime is 221045771. The next prime is 221045827. The reversal of 221045823 is 328540122.

It is not a de Polignac number, because 221045823 - 2⁹ = 221045311 is a prime.

It is a super-2 number, since 2×221045823² = 97722511731494658, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221045827) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12280315 + ... + 12280332.

Almost surely, 2^221045823 is an apocalyptic number.

221045823 is a deficient number, since it is larger than the sum of its proper divisors (98242601).

221045823 is a wasteful number, since it uses less digits than its factorization.

221045823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24560653 (or 24560650 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 221045823 is about 14867.6098617094. The cubic root of 221045823 is about 604.6361430293.

Adding to 221045823 its reverse (328540122), we get a palindrome (549585945).

The spelling of 221045823 in words is "two hundred twenty-one million, forty-five thousand, eight hundred twenty-three".