21422361 has 16 divisors (see below), whose sum is σ = 30220416. Its totient is φ = 13470336.

The previous prime is 21422347. The next prime is 21422381. The reversal of 21422361 is 16322412.

It is not a de Polignac number, because 21422361 - 2⁹ = 21421849 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21422321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2911 + ... + 7163.

It is an arithmetic number, because the mean of its divisors is an integer number (1888776).

Almost surely, 2^21422361 is an apocalyptic number.

It is an amenable number.

21422361 is a deficient number, since it is larger than the sum of its proper divisors (8798055).

21422361 is a wasteful number, since it uses less digits than its factorization.

21422361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4352.

The product of its digits is 576, while the sum is 21.

The square root of 21422361 is about 4628.4296472994. The cubic root of 21422361 is about 277.7297764108.

Subtracting from 21422361 its product of digits (576), we obtain a triangular number (21421785 = T₆₅₄₅).

Adding to 21422361 its reverse (16322412), we get a palindrome (37744773).

The spelling of 21422361 in words is "twenty-one million, four hundred twenty-two thousand, three hundred sixty-one".