221152621 has 2 divisors, whose sum is σ = 221152622. Its totient is φ = 221152620.

The previous prime is 221152619. The next prime is 221152627. The reversal of 221152621 is 126251122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 221116900 + 35721 = 14870^2 + 189^2 .

It is a cyclic number.

It is not a de Polignac number, because 221152621 - 2¹ = 221152619 is a prime.

Together with 221152619, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 221152592 and 221152601.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221152627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110576310 + 110576311.

It is an arithmetic number, because the mean of its divisors is an integer number (110576311).

Almost surely, 2^221152621 is an apocalyptic number.

It is an amenable number.

221152621 is a deficient number, since it is larger than the sum of its proper divisors (1).

221152621 is an equidigital number, since it uses as much as digits as its factorization.

221152621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 480, while the sum is 22.

The square root of 221152621 is about 14871.2010611114. The cubic root of 221152621 is about 604.7335037380.

The spelling of 221152621 in words is "two hundred twenty-one million, one hundred fifty-two thousand, six hundred twenty-one".