21418367 has 2 divisors, whose sum is σ = 21418368. Its totient is φ = 21418366.

The previous prime is 21418349. The next prime is 21418373. The reversal of 21418367 is 76381412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21418367 - 2¹⁰ = 21417343 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21418337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10709183 + 10709184.

It is an arithmetic number, because the mean of its divisors is an integer number (10709184).

Almost surely, 2^21418367 is an apocalyptic number.

21418367 is a deficient number, since it is larger than the sum of its proper divisors (1).

21418367 is an equidigital number, since it uses as much as digits as its factorization.

21418367 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8064, while the sum is 32.

The square root of 21418367 is about 4627.9981633531. The cubic root of 21418367 is about 277.7125152933.

Adding to 21418367 its reverse (76381412), we get a palindrome (97799779).

It can be divided in two parts, 214 and 18367, that added together give a palindrome (18581).

The spelling of 21418367 in words is "twenty-one million, four hundred eighteen thousand, three hundred sixty-seven".