221353312381 has 2 divisors, whose sum is σ = 221353312382. Its totient is φ = 221353312380.

The previous prime is 221353312283. The next prime is 221353312451. The reversal of 221353312381 is 183213353122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 167501932900 + 53851379481 = 409270^2 + 232059^2 .

It is a cyclic number.

It is not a de Polignac number, because 221353312381 - 2²⁵ = 221319757949 is a prime.

It is a super-2 number, since 2×221353312381² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221353312681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110676656190 + 110676656191.

It is an arithmetic number, because the mean of its divisors is an integer number (110676656191).

Almost surely, 2^221353312381 is an apocalyptic number.

It is an amenable number.

221353312381 is a deficient number, since it is larger than the sum of its proper divisors (1).

221353312381 is an equidigital number, since it uses as much as digits as its factorization.

221353312381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25920, while the sum is 34.

The spelling of 221353312381 in words is "two hundred twenty-one billion, three hundred fifty-three million, three hundred twelve thousand, three hundred eighty-one".