221645266379 has 2 divisors, whose sum is σ = 221645266380. Its totient is φ = 221645266378.

The previous prime is 221645266313. The next prime is 221645266417. The reversal of 221645266379 is 973662546122.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221645266379 is a prime.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221645266379.

It is not a weakly prime, because it can be changed into another prime (221645266079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110822633189 + 110822633190.

It is an arithmetic number, because the mean of its divisors is an integer number (110822633190).

Almost surely, 2^221645266379 is an apocalyptic number.

221645266379 is a deficient number, since it is larger than the sum of its proper divisors (1).

221645266379 is an equidigital number, since it uses as much as digits as its factorization.

221645266379 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6531840, while the sum is 53.

The spelling of 221645266379 in words is "two hundred twenty-one billion, six hundred forty-five million, two hundred sixty-six thousand, three hundred seventy-nine".