68627281 has 4 divisors (see below), whose sum is σ = 68643892. Its totient is φ = 68610672.

The previous prime is 68627263. The next prime is 68627287. The reversal of 68627281 is 18272686.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 20394256 + 48233025 = 4516^2 + 6945^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68627281 is a prime.

It is a super-2 number, since 2×68627281² = 9419407394905922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68627287) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3271 + ... + 12163.

It is an arithmetic number, because the mean of its divisors is an integer number (17160973).

Almost surely, 2^68627281 is an apocalyptic number.

It is an amenable number.

68627281 is a deficient number, since it is larger than the sum of its proper divisors (16611).

68627281 is an equidigital number, since it uses as much as digits as its factorization.

68627281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16610.

The product of its digits is 64512, while the sum is 40.

The square root of 68627281 is about 8284.1584364376. The cubic root of 68627281 is about 409.4167415511.

The spelling of 68627281 in words is "sixty-eight million, six hundred twenty-seven thousand, two hundred eighty-one".