221521225865 has 8 divisors (see below), whose sum is σ = 281462263560. Its totient is φ = 166792452352.

The previous prime is 221521225843. The next prime is 221521225901. The reversal of 221521225865 is 568522125122.

It can be written as a sum of positive squares in 4 ways, for example, as 16490669056 + 205030556809 = 128416^2 + 452803^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 221521225865 - 2³⁶ = 152801749129 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1303065950 + ... + 1303066119.

It is an arithmetic number, because the mean of its divisors is an integer number (35182782945).

Almost surely, 2^221521225865 is an apocalyptic number.

It is an amenable number.

221521225865 is a deficient number, since it is larger than the sum of its proper divisors (59941037695).

221521225865 is a wasteful number, since it uses less digits than its factorization.

221521225865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2606132091.

The product of its digits is 192000, while the sum is 41.

The spelling of 221521225865 in words is "two hundred twenty-one billion, five hundred twenty-one million, two hundred twenty-five thousand, eight hundred sixty-five".