21099360 has 96 divisors (see below), whose sum is σ = 67223520. Its totient is φ = 5562368.

The previous prime is 21099301. The next prime is 21099371. The reversal of 21099360 is 6399012.

21099360 is nontrivially palindromic in base 14.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

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, 54046 + ... + 54434.

It is an arithmetic number, because the mean of its divisors is an integer number (700245).

Almost surely, 2^21099360 is an apocalyptic number.

21099360 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21099360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33611760).

21099360 is an abundant number, since it is smaller than the sum of its proper divisors (46124160).

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

21099360 is a wasteful number, since it uses less digits than its factorization.

21099360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 520 (or 512 counting only the distinct ones).

The product of its (nonzero) digits is 2916, while the sum is 30.

The square root of 21099360 is about 4593.4039665590. The cubic root of 21099360 is about 276.3268549429.

The spelling of 21099360 in words is "twenty-one million, ninety-nine thousand, three hundred sixty".