68537321 has 4 divisors (see below), whose sum is σ = 69830532. Its totient is φ = 67244112.

The previous prime is 68537299. The next prime is 68537323. The reversal of 68537321 is 12373586.

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 57214096 + 11323225 = 7564^2 + 3365^2 .

It is a cyclic number.

It is not a de Polignac number, because 68537321 - 2²² = 64343017 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (68537323) 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, 646526 + ... + 646631.

It is an arithmetic number, because the mean of its divisors is an integer number (17457633).

Almost surely, 2^68537321 is an apocalyptic number.

It is an amenable number.

68537321 is a deficient number, since it is larger than the sum of its proper divisors (1293211).

68537321 is a wasteful number, since it uses less digits than its factorization.

68537321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1293210.

The product of its digits is 30240, while the sum is 35.

The square root of 68537321 is about 8278.7270156709. The cubic root of 68537321 is about 409.2377688228.

The spelling of 68537321 in words is "sixty-eight million, five hundred thirty-seven thousand, three hundred twenty-one".