21525016 has 16 divisors (see below), whose sum is σ = 40425840. Its totient is φ = 10744800.

The previous prime is 21525001. The next prime is 21525017. The reversal of 21525016 is 61052512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21525017) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3966 + ... + 7666.

It is an arithmetic number, because the mean of its divisors is an integer number (2526615).

Almost surely, 2^21525016 is an apocalyptic number.

It is an amenable number.

21525016 is a deficient number, since it is larger than the sum of its proper divisors (18900824).

21525016 is a wasteful number, since it uses less digits than its factorization.

21525016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4434 (or 4430 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 22.

The square root of 21525016 is about 4639.5060081866. The cubic root of 21525016 is about 278.1726925914.

Adding to 21525016 its reverse (61052512), we get a palindrome (82577528).

It can be divided in two parts, 215250 and 16, that multiplied together give a triangular number (3444000 = T₂₆₂₄).

The spelling of 21525016 in words is "twenty-one million, five hundred twenty-five thousand, sixteen".