21365337 has 16 divisors (see below), whose sum is σ = 32817152. Its totient is φ = 12111120.

The previous prime is 21365303. The next prime is 21365347. The reversal of 21365337 is 73356312.

It is not a de Polignac number, because 21365337 - 2¹¹ = 21363289 is a prime.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21365347) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1339 + ... + 6672.

It is an arithmetic number, because the mean of its divisors is an integer number (2051072).

Almost surely, 2^21365337 is an apocalyptic number.

It is an amenable number.

21365337 is a deficient number, since it is larger than the sum of its proper divisors (11451815).

21365337 is a wasteful number, since it uses less digits than its factorization.

21365337 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8148.

The product of its digits is 11340, while the sum is 30.

The square root of 21365337 is about 4622.2653536983. The cubic root of 21365337 is about 277.4831285904.

The spelling of 21365337 in words is "twenty-one million, three hundred sixty-five thousand, three hundred thirty-seven".