21318598 has 16 divisors (see below), whose sum is σ = 36643104. Its totient is φ = 9112320.

The previous prime is 21318541. The next prime is 21318599. The reversal of 21318598 is 89581312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21318599) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4086 + ... + 7702.

It is an arithmetic number, because the mean of its divisors is an integer number (2290194).

Almost surely, 2^21318598 is an apocalyptic number.

21318598 is a deficient number, since it is larger than the sum of its proper divisors (15324506).

21318598 is a wasteful number, since it uses less digits than its factorization.

21318598 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4047.

The product of its digits is 17280, while the sum is 37.

The square root of 21318598 is about 4617.2067313474. The cubic root of 21318598 is about 277.2806393481.

The spelling of 21318598 in words is "twenty-one million, three hundred eighteen thousand, five hundred ninety-eight".