221262913 has 2 divisors, whose sum is σ = 221262914. Its totient is φ = 221262912.

The previous prime is 221262911. The next prime is 221262919. The reversal of 221262913 is 319262122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 192016449 + 29246464 = 13857^2 + 5408^2 .

It is a cyclic number.

It is not a de Polignac number, because 221262913 - 2¹ = 221262911 is a prime.

Together with 221262911, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (221262911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110631456 + 110631457.

It is an arithmetic number, because the mean of its divisors is an integer number (110631457).

Almost surely, 2^221262913 is an apocalyptic number.

It is an amenable number.

221262913 is a deficient number, since it is larger than the sum of its proper divisors (1).

221262913 is an equidigital number, since it uses as much as digits as its factorization.

221262913 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2592, while the sum is 28.

The square root of 221262913 is about 14874.9088400568. The cubic root of 221262913 is about 604.8340168026.

The spelling of 221262913 in words is "two hundred twenty-one million, two hundred sixty-two thousand, nine hundred thirteen".