221521225901 has 2 divisors, whose sum is σ = 221521225902. Its totient is φ = 221521225900.

The previous prime is 221521225843. The next prime is 221521225949. The reversal of 221521225901 is 109522125122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 219281475625 + 2239750276 = 468275^2 + 47326^2 .

It is a cyclic number.

It is not a de Polignac number, because 221521225901 - 2¹⁰ = 221521224877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221521224901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110760612950 + 110760612951.

It is an arithmetic number, because the mean of its divisors is an integer number (110760612951).

Almost surely, 2^221521225901 is an apocalyptic number.

It is an amenable number.

221521225901 is a deficient number, since it is larger than the sum of its proper divisors (1).

221521225901 is an equidigital number, since it uses as much as digits as its factorization.

221521225901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7200, while the sum is 32.

The spelling of 221521225901 in words is "two hundred twenty-one billion, five hundred twenty-one million, two hundred twenty-five thousand, nine hundred one".