21318594 has 16 divisors (see below), whose sum is σ = 46513440. Its totient is φ = 6460160.

The previous prime is 21318541. The next prime is 21318599. The reversal of 21318594 is 49581312.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (21318599) 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 7 ways as a sum of consecutive naturals, for example, 161439 + ... + 161570.

It is an arithmetic number, because the mean of its divisors is an integer number (2907090).

Almost surely, 2^21318594 is an apocalyptic number.

21318594 is an abundant number, since it is smaller than the sum of its proper divisors (25194846).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21318594 is a wasteful number, since it uses less digits than its factorization.

21318594 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 323025.

The product of its digits is 8640, while the sum is 33.

The square root of 21318594 is about 4617.2062981851. The cubic root of 21318594 is about 277.2806220061.

It can be divided in two parts, 21318 and 594, that added together give a palindrome (21912).

The spelling of 21318594 in words is "twenty-one million, three hundred eighteen thousand, five hundred ninety-four".