221521992113 has 2 divisors, whose sum is σ = 221521992114. Its totient is φ = 221521992112.

The previous prime is 221521992073. The next prime is 221521992143. The reversal of 221521992113 is 311299125122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 182186409889 + 39335582224 = 426833^2 + 198332^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221521992113 is a prime.

It is not a weakly prime, because it can be changed into another prime (221521992143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110760996056 + 110760996057.

It is an arithmetic number, because the mean of its divisors is an integer number (110760996057).

Almost surely, 2^221521992113 is an apocalyptic number.

It is an amenable number.

221521992113 is a deficient number, since it is larger than the sum of its proper divisors (1).

221521992113 is an equidigital number, since it uses as much as digits as its factorization.

221521992113 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19440, while the sum is 38.

The spelling of 221521992113 in words is "two hundred twenty-one billion, five hundred twenty-one million, nine hundred ninety-two thousand, one hundred thirteen".