21097360 has 80 divisors (see below), whose sum is σ = 51996672. Its totient is φ = 7948800.

The previous prime is 21097337. The next prime is 21097369. The reversal of 21097360 is 6379012.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (21097369) 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 15 ways as a sum of consecutive naturals, for example, 116470 + ... + 116650.

Almost surely, 2^21097360 is an apocalyptic number.

21097360 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 21097360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25998336).

21097360 is an abundant number, since it is smaller than the sum of its proper divisors (30899312).

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

21097360 is a wasteful number, since it uses less digits than its factorization.

21097360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 272 (or 266 counting only the distinct ones).

The product of its (nonzero) digits is 2268, while the sum is 28.

The square root of 21097360 is about 4593.1862579260. The cubic root of 21097360 is about 276.3181236959.

The spelling of 21097360 in words is "twenty-one million, ninety-seven thousand, three hundred sixty".