221644612523 has 2 divisors, whose sum is σ = 221644612524. Its totient is φ = 221644612522.

The previous prime is 221644612451. The next prime is 221644612547. The reversal of 221644612523 is 325216446122.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221644612523 - 2¹⁸ = 221644350379 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (221644612573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110822306261 + 110822306262.

It is an arithmetic number, because the mean of its divisors is an integer number (110822306262).

Almost surely, 2^221644612523 is an apocalyptic number.

221644612523 is a deficient number, since it is larger than the sum of its proper divisors (1).

221644612523 is an equidigital number, since it uses as much as digits as its factorization.

221644612523 is an evil number, because the sum of its binary digits is even.

The product of its digits is 138240, while the sum is 38.

The spelling of 221644612523 in words is "two hundred twenty-one billion, six hundred forty-four million, six hundred twelve thousand, five hundred twenty-three".