21526316 has 48 divisors (see below), whose sum is σ = 46421760. Its totient is φ = 8527680.

The previous prime is 21526303. The next prime is 21526333. The reversal of 21526316 is 61362512.

It is a zygodrome in base 3.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22406 + ... + 23346.

It is an arithmetic number, because the mean of its divisors is an integer number (967120).

Almost surely, 2^21526316 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21526316, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23210880).

21526316 is an abundant number, since it is smaller than the sum of its proper divisors (24895444).

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

21526316 is a wasteful number, since it uses less digits than its factorization.

21526316 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1014 (or 1012 counting only the distinct ones).

The product of its digits is 2160, while the sum is 26.

The square root of 21526316 is about 4639.6461071940. The cubic root of 21526316 is about 278.1782925442.

Adding to 21526316 its reverse (61362512), we get a palindrome (82888828).

The spelling of 21526316 in words is "twenty-one million, five hundred twenty-six thousand, three hundred sixteen".