21525116 has 12 divisors (see below), whose sum is σ = 37806888. Its totient is φ = 10723152.

The previous prime is 21525109. The next prime is 21525121. The reversal of 21525116 is 61152512.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21525091 and 21525100.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8606 + ... + 10821.

It is an arithmetic number, because the mean of its divisors is an integer number (3150574).

Almost surely, 2^21525116 is an apocalyptic number.

It is an amenable number.

21525116 is a deficient number, since it is larger than the sum of its proper divisors (16281772).

21525116 is a wasteful number, since it uses less digits than its factorization.

21525116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19708 (or 19706 counting only the distinct ones).

The product of its digits is 600, while the sum is 23.

The square root of 21525116 is about 4639.5167851836. The cubic root of 21525116 is about 278.1731233650.

Adding to 21525116 its reverse (61152512), we get a palindrome (82677628).

The spelling of 21525116 in words is "twenty-one million, five hundred twenty-five thousand, one hundred sixteen".