21525549 has 8 divisors (see below), whose sum is σ = 28813440. Its totient is φ = 14294016.

The previous prime is 21525547. The next prime is 21525551. The reversal of 21525549 is 94552512.

It is an interprime number because it is at equal distance from previous prime (21525547) and next prime (21525551).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21525549 - 2¹ = 21525547 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21525541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13189 + ... + 14730.

It is an arithmetic number, because the mean of its divisors is an integer number (3601680).

Almost surely, 2^21525549 is an apocalyptic number.

It is an amenable number.

21525549 is a deficient number, since it is larger than the sum of its proper divisors (7287891).

21525549 is a wasteful number, since it uses less digits than its factorization.

21525549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28179.

The product of its digits is 18000, while the sum is 33.

The square root of 21525549 is about 4639.5634492913. The cubic root of 21525549 is about 278.1749885993.

The spelling of 21525549 in words is "twenty-one million, five hundred twenty-five thousand, five hundred forty-nine".