21400367 has 2 divisors, whose sum is σ = 21400368. Its totient is φ = 21400366.

The previous prime is 21400361. The next prime is 21400381. The reversal of 21400367 is 76300412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21400367 - 2¹⁸ = 21138223 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21400361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10700183 + 10700184.

It is an arithmetic number, because the mean of its divisors is an integer number (10700184).

Almost surely, 2^21400367 is an apocalyptic number.

21400367 is a deficient number, since it is larger than the sum of its proper divisors (1).

21400367 is an equidigital number, since it uses as much as digits as its factorization.

21400367 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 23.

The square root of 21400367 is about 4626.0530693022. The cubic root of 21400367 is about 277.6346969382.

Adding to 21400367 its reverse (76300412), we get a palindrome (97700779).

The spelling of 21400367 in words is "twenty-one million, four hundred thousand, three hundred sixty-seven".