67800021 has 16 divisors (see below), whose sum is σ = 96883584. Its totient is φ = 42064704.

The previous prime is 67800001. The next prime is 67800023. The reversal of 67800021 is 12000876.

It is not a de Polignac number, because 67800021 - 2⁹ = 67799509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 67799964 and 67800000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (67800023) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10726 + ... + 15831.

It is an arithmetic number, because the mean of its divisors is an integer number (6055224).

Almost surely, 2^67800021 is an apocalyptic number.

It is an amenable number.

67800021 is a deficient number, since it is larger than the sum of its proper divisors (29083563).

67800021 is a wasteful number, since it uses less digits than its factorization.

67800021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26620.

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 67800021 is about 8234.0768152842. The cubic root of 67800021 is about 407.7649970682.

Adding to 67800021 its reverse (12000876), we get a palindrome (79800897).

The spelling of 67800021 in words is "sixty-seven million, eight hundred thousand, twenty-one".