21318099 has 8 divisors (see below), whose sum is σ = 31008192. Its totient is φ = 12920040.

The previous prime is 21318091. The next prime is 21318109. The reversal of 21318099 is 99081312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21318099 - 2³ = 21318091 is a prime.

It is a super-2 number, since 2×21318099² = 908922689947602, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33), and also a Moran number because the ratio is a prime number: 646003 = 21318099 / (2 + 1 + 3 + 1 + 8 + 0 + 9 + 9).

It is not an unprimeable number, because it can be changed into a prime (21318091) 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, 322969 + ... + 323034.

It is an arithmetic number, because the mean of its divisors is an integer number (3876024).

Almost surely, 2^21318099 is an apocalyptic number.

21318099 is a deficient number, since it is larger than the sum of its proper divisors (9690093).

21318099 is a wasteful number, since it uses less digits than its factorization.

21318099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 646017.

The product of its (nonzero) digits is 3888, while the sum is 33.

The square root of 21318099 is about 4617.1526940312. The cubic root of 21318099 is about 277.2784759145.

The spelling of 21318099 in words is "twenty-one million, three hundred eighteen thousand, ninety-nine".