221906051 has 2 divisors, whose sum is σ = 221906052. Its totient is φ = 221906050.

The previous prime is 221906033. The next prime is 221906053. The reversal of 221906051 is 150609122.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221906051 is a prime.

Together with 221906053, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221906051.

It is not a weakly prime, because it can be changed into another prime (221906053) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110953025 + 110953026.

It is an arithmetic number, because the mean of its divisors is an integer number (110953026).

Almost surely, 2^221906051 is an apocalyptic number.

221906051 is a deficient number, since it is larger than the sum of its proper divisors (1).

221906051 is an equidigital number, since it uses as much as digits as its factorization.

221906051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 221906051 is about 14896.5113701162. The cubic root of 221906051 is about 605.4194673149.

The spelling of 221906051 in words is "two hundred twenty-one million, nine hundred six thousand, fifty-one".