67839921 has 12 divisors (see below), whose sum is σ = 98641920. Its totient is φ = 44926200.

The previous prime is 67839913. The next prime is 67839929. The reversal of 67839921 is 12993876.

It is an interprime number because it is at equal distance from previous prime (67839913) and next prime (67839929).

It is not a de Polignac number, because 67839921 - 2³ = 67839913 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (67839929) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 23601 + ... + 26318.

It is an arithmetic number, because the mean of its divisors is an integer number (8220160).

Almost surely, 2^67839921 is an apocalyptic number.

It is an amenable number.

67839921 is a deficient number, since it is larger than the sum of its proper divisors (30801999).

67839921 is a wasteful number, since it uses less digits than its factorization.

67839921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50076 (or 50073 counting only the distinct ones).

The product of its digits is 163296, while the sum is 45.

The square root of 67839921 is about 8236.4993170643. The cubic root of 67839921 is about 407.8449706563.

The spelling of 67839921 in words is "sixty-seven million, eight hundred thirty-nine thousand, nine hundred twenty-one".