221356901 has 2 divisors, whose sum is σ = 221356902. Its totient is φ = 221356900.

The previous prime is 221356879. The next prime is 221356921. The reversal of 221356901 is 109653122.

221356901 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 205348900 + 16008001 = 14330^2 + 4001^2 .

It is a cyclic number.

It is not a de Polignac number, because 221356901 - 2¹⁰ = 221355877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221356921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110678450 + 110678451.

It is an arithmetic number, because the mean of its divisors is an integer number (110678451).

Almost surely, 2^221356901 is an apocalyptic number.

It is an amenable number.

221356901 is a deficient number, since it is larger than the sum of its proper divisors (1).

221356901 is an equidigital number, since it uses as much as digits as its factorization.

221356901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 29.

The square root of 221356901 is about 14878.0677844941. The cubic root of 221356901 is about 604.9196450891.

The spelling of 221356901 in words is "two hundred twenty-one million, three hundred fifty-six thousand, nine hundred one".