68542021 has 4 divisors (see below), whose sum is σ = 68729152. Its totient is φ = 68354892.

The previous prime is 68542009. The next prime is 68542031. The reversal of 68542021 is 12024586.

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 not a de Polignac number, because 68542021 - 2²¹ = 66444869 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 (68542031) 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, 93015 + ... + 93748.

It is an arithmetic number, because the mean of its divisors is an integer number (17182288).

Almost surely, 2^68542021 is an apocalyptic number.

It is an amenable number.

68542021 is a deficient number, since it is larger than the sum of its proper divisors (187131).

68542021 is a wasteful number, since it uses less digits than its factorization.

68542021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187130.

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 68542021 is about 8279.0108708710. The cubic root of 68542021 is about 409.2471232082.

The spelling of 68542021 in words is "sixty-eight million, five hundred forty-two thousand, twenty-one".