13866421 has 2 divisors, whose sum is σ = 13866422. Its totient is φ = 13866420.

The previous prime is 13866389. The next prime is 13866427. The reversal of 13866421 is 12466831.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13242321 + 624100 = 3639^2 + 790^2 .

It is a cyclic number.

It is not a de Polignac number, because 13866421 - 2⁵ = 13866389 is a prime.

It is equal to p₉₀₁₉₇₅ and since 13866421 and 901975 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13866427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6933210 + 6933211.

It is an arithmetic number, because the mean of its divisors is an integer number (6933211).

Almost surely, 2^13866421 is an apocalyptic number.

It is an amenable number.

13866421 is a deficient number, since it is larger than the sum of its proper divisors (1).

13866421 is an equidigital number, since it uses as much as digits as its factorization.

13866421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6912, while the sum is 31.

The square root of 13866421 is about 3723.7643588176. The cubic root of 13866421 is about 240.2452412159.

The spelling of 13866421 in words is "thirteen million, eight hundred sixty-six thousand, four hundred twenty-one".