21047360 has 112 divisors (see below), whose sum is σ = 54809136. Its totient is φ = 7667712.

The previous prime is 21047333. The next prime is 21047363. The reversal of 21047360 is 6374012.

It can be written as a sum of positive squares in 8 ways, for example, as 1048576 + 19998784 = 1024^2 + 4472^2 .

It is not an unprimeable number, because it can be changed into a prime (21047363) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 288284 + ... + 288356.

Almost surely, 2^21047360 is an apocalyptic number.

21047360 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 21047360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27404568).

21047360 is an abundant number, since it is smaller than the sum of its proper divisors (33761776).

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

21047360 is a wasteful number, since it uses less digits than its factorization.

21047360 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160 (or 150 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 23.

The square root of 21047360 is about 4587.7401844481. The cubic root of 21047360 is about 276.0996629504.

The spelling of 21047360 in words is "twenty-one million, forty-seven thousand, three hundred sixty".