21023360 has 64 divisors (see below), whose sum is σ = 50893920. Its totient is φ = 8303616.

The previous prime is 21023341. The next prime is 21023381. The reversal of 21023360 is 6332012.

It is a tau number, because it is divible by the number of its divisors (64).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68327 + ... + 68633.

Almost surely, 2^21023360 is an apocalyptic number.

21023360 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 21023360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25446960).

21023360 is an abundant number, since it is smaller than the sum of its proper divisors (29870560).

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

21023360 is a wasteful number, since it uses less digits than its factorization.

21023360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 433 (or 421 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 17.

The square root of 21023360 is about 4585.1237715028. The cubic root of 21023360 is about 275.9946788864.

Adding to 21023360 its reverse (6332012), we get a palindrome (27355372).

The spelling of 21023360 in words is "twenty-one million, twenty-three thousand, three hundred sixty".