21589008 has 120 divisors (see below), whose sum is σ = 66326112. Its totient is φ = 6031872.

The previous prime is 21589003. The next prime is 21589013. The reversal of 21589008 is 80098512.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21589003) and next prime (21589013).

It is a self number, because there is not a number n which added to its sum of digits gives 21589008.

It is not an unprimeable number, because it can be changed into a prime (21589003) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 157516 + ... + 157652.

Almost surely, 2^21589008 is an apocalyptic number.

21589008 is a gapful number since it is divisible by the number (28) 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 21589008, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33163056).

21589008 is an abundant number, since it is smaller than the sum of its proper divisors (44737104).

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

21589008 is a wasteful number, since it uses less digits than its factorization.

21589008 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 229 (or 216 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 33.

The square root of 21589008 is about 4646.3973140488. The cubic root of 21589008 is about 278.4480809413.

The spelling of 21589008 in words is "twenty-one million, five hundred eighty-nine thousand, eight".