67871821 has 2 divisors, whose sum is σ = 67871822. Its totient is φ = 67871820.

The previous prime is 67871809. The next prime is 67871831. The reversal of 67871821 is 12817876.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58690921 + 9180900 = 7661^2 + 3030^2 .

It is a cyclic number.

It is not a de Polignac number, because 67871821 - 2⁵ = 67871789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (67871831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33935910 + 33935911.

It is an arithmetic number, because the mean of its divisors is an integer number (33935911).

Almost surely, 2^67871821 is an apocalyptic number.

It is an amenable number.

67871821 is a deficient number, since it is larger than the sum of its proper divisors (1).

67871821 is an equidigital number, since it uses as much as digits as its factorization.

67871821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 37632, while the sum is 40.

The square root of 67871821 is about 8238.4355917856. The cubic root of 67871821 is about 407.9088868856.

The spelling of 67871821 in words is "sixty-seven million, eight hundred seventy-one thousand, eight hundred twenty-one".