68742821 has 4 divisors (see below), whose sum is σ = 78563232. Its totient is φ = 58922412.

The previous prime is 68742809. The next prime is 68742829. The reversal of 68742821 is 12824786.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68742821 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68742829) 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, 4910195 + ... + 4910208.

It is an arithmetic number, because the mean of its divisors is an integer number (19640808).

Almost surely, 2^68742821 is an apocalyptic number.

It is an amenable number.

68742821 is a deficient number, since it is larger than the sum of its proper divisors (9820411).

68742821 is an equidigital number, since it uses as much as digits as its factorization.

68742821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9820410.

The product of its digits is 43008, while the sum is 38.

The square root of 68742821 is about 8291.1290545981. The cubic root of 68742821 is about 409.6463756345.

The spelling of 68742821 in words is "sixty-eight million, seven hundred forty-two thousand, eight hundred twenty-one".