221962681 has 2 divisors, whose sum is σ = 221962682. Its totient is φ = 221962680.

The previous prime is 221962679. The next prime is 221962703. The reversal of 221962681 is 186269122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 217297081 + 4665600 = 14741^2 + 2160^2 .

It is a cyclic number.

It is not a de Polignac number, because 221962681 - 2¹ = 221962679 is a prime.

It is a super-2 number, since 2×221962681² = 98534863513415522, which contains 22 as substring.

Together with 221962679, 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 221962681.

It is not a weakly prime, because it can be changed into another prime (221962621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110981340 + 110981341.

It is an arithmetic number, because the mean of its divisors is an integer number (110981341).

Almost surely, 2^221962681 is an apocalyptic number.

It is an amenable number.

221962681 is a deficient number, since it is larger than the sum of its proper divisors (1).

221962681 is an equidigital number, since it uses as much as digits as its factorization.

221962681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 37.

The square root of 221962681 is about 14898.4120294748. The cubic root of 221962681 is about 605.4709635648.

The spelling of 221962681 in words is "two hundred twenty-one million, nine hundred sixty-two thousand, six hundred eighty-one".