68626781 has 4 divisors (see below), whose sum is σ = 68646492. Its totient is φ = 68607072.

The previous prime is 68626759. The next prime is 68626783. The reversal of 68626781 is 18762686.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 32024281 + 36602500 = 5659^2 + 6050^2 .

It is a cyclic number.

It is not a de Polignac number, because 68626781 - 2¹⁴ = 68610397 is a prime.

It is a super-2 number, since 2×68626781² = 9419270140843922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68626783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3080 + ... + 12113.

It is an arithmetic number, because the mean of its divisors is an integer number (17161623).

Almost surely, 2^68626781 is an apocalyptic number.

It is an amenable number.

68626781 is a deficient number, since it is larger than the sum of its proper divisors (19711).

68626781 is a wasteful number, since it uses less digits than its factorization.

68626781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19710.

The product of its digits is 193536, while the sum is 44.

The square root of 68626781 is about 8284.1282583021. The cubic root of 68626781 is about 409.4157472484.

The spelling of 68626781 in words is "sixty-eight million, six hundred twenty-six thousand, seven hundred eighty-one".