68022781 has 2 divisors, whose sum is σ = 68022782. Its totient is φ = 68022780.

The previous prime is 68022769. The next prime is 68022791. The reversal of 68022781 is 18722086.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60684100 + 7338681 = 7790^2 + 2709^2 .

It is a cyclic number.

It is not a de Polignac number, because 68022781 - 2⁷ = 68022653 is a prime.

It is a super-2 number, since 2×68022781² = 9254197469947922, which contains 22 as substring.

It is a plaindrome in base 13.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68022701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34011390 + 34011391.

It is an arithmetic number, because the mean of its divisors is an integer number (34011391).

Almost surely, 2^68022781 is an apocalyptic number.

It is an amenable number.

68022781 is a deficient number, since it is larger than the sum of its proper divisors (1).

68022781 is an equidigital number, since it uses as much as digits as its factorization.

68022781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10752, while the sum is 34.

The square root of 68022781 is about 8247.5924365841. The cubic root of 68022781 is about 408.2110855854.

The spelling of 68022781 in words is "sixty-eight million, twenty-two thousand, seven hundred eighty-one".