21418379 has 2 divisors, whose sum is σ = 21418380. Its totient is φ = 21418378.

The previous prime is 21418373. The next prime is 21418403. The reversal of 21418379 is 97381412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21418379 - 2¹⁶ = 21352843 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21418373) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10709189 + 10709190.

It is an arithmetic number, because the mean of its divisors is an integer number (10709190).

Almost surely, 2^21418379 is an apocalyptic number.

21418379 is a deficient number, since it is larger than the sum of its proper divisors (1).

21418379 is an equidigital number, since it uses as much as digits as its factorization.

21418379 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 21418379 is about 4627.9994598098. Note that the first 3 decimals coincide. The cubic root of 21418379 is about 277.7125671577.

The spelling of 21418379 in words is "twenty-one million, four hundred eighteen thousand, three hundred seventy-nine".