21184379 has 2 divisors, whose sum is σ = 21184380. Its totient is φ = 21184378.

The previous prime is 21184349. The next prime is 21184391. The reversal of 21184379 is 97348112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21184379 - 2²⁴ = 4407163 is a prime.

It is not a weakly prime, because it can be changed into another prime (21184349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10592189 + 10592190.

It is an arithmetic number, because the mean of its divisors is an integer number (10592190).

Almost surely, 2^21184379 is an apocalyptic number.

21184379 is a deficient number, since it is larger than the sum of its proper divisors (1).

21184379 is an equidigital number, since it uses as much as digits as its factorization.

21184379 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12096, while the sum is 35.

The square root of 21184379 is about 4602.6491284911. The cubic root of 21184379 is about 276.6975067636.

The spelling of 21184379 in words is "twenty-one million, one hundred eighty-four thousand, three hundred seventy-nine".