68020021 has 4 divisors (see below), whose sum is σ = 68043712. Its totient is φ = 67996332.

The previous prime is 68019961. The next prime is 68020031. The reversal of 68020021 is 12002086.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12002086 = 2 ⋅6001043.

It is a cyclic number.

It is not a de Polignac number, because 68020021 - 2¹⁷ = 67888949 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 (68020031) 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, 6831 + ... + 13516.

It is an arithmetic number, because the mean of its divisors is an integer number (17010928).

Almost surely, 2^68020021 is an apocalyptic number.

It is an amenable number.

68020021 is a deficient number, since it is larger than the sum of its proper divisors (23691).

68020021 is a wasteful number, since it uses less digits than its factorization.

68020021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23690.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 68020021 is about 8247.4251133308. The cubic root of 68020021 is about 408.2055645045.

The spelling of 68020021 in words is "sixty-eight million, twenty thousand, twenty-one".