21379584 has 80 divisors (see below), whose sum is σ = 58924800. Its totient is φ = 6881280.

The previous prime is 21379571. The next prime is 21379609. The reversal of 21379584 is 48597312.

It is a super-2 number, since 2×21379584² = 914173224026112, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47392 + ... + 47840.

It is an arithmetic number, because the mean of its divisors is an integer number (736560).

Almost surely, 2^21379584 is an apocalyptic number.

21379584 is a gapful number since it is divisible by the number (24) 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 21379584, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29462400).

21379584 is an abundant number, since it is smaller than the sum of its proper divisors (37545216).

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

21379584 is an equidigital number, since it uses as much as digits as its factorization.

21379584 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 501 (or 485 counting only the distinct ones).

The product of its digits is 60480, while the sum is 39.

The square root of 21379584 is about 4623.8062243135. The cubic root of 21379584 is about 277.5447927045.

It can be divided in two parts, 213 and 79584, that added together give a palindrome (79797).

The spelling of 21379584 in words is "twenty-one million, three hundred seventy-nine thousand, five hundred eighty-four".