21525189 has 8 divisors (see below), whose sum is σ = 32800320. Its totient is φ = 12300096.

The previous prime is 21525181. The next prime is 21525197. The reversal of 21525189 is 98152512.

It is an interprime number because it is at equal distance from previous prime (21525181) and next prime (21525197).

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

It is not a de Polignac number, because 21525189 - 2³ = 21525181 is a prime.

It is a super-2 number, since 2×21525189² = 926667522971442, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21525181) 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, 512484 + ... + 512525.

It is an arithmetic number, because the mean of its divisors is an integer number (4100040).

Almost surely, 2^21525189 is an apocalyptic number.

It is an amenable number.

21525189 is a deficient number, since it is larger than the sum of its proper divisors (11275131).

21525189 is a wasteful number, since it uses less digits than its factorization.

21525189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1025019.

The product of its digits is 7200, while the sum is 33.

The square root of 21525189 is about 4639.5246523755. The cubic root of 21525189 is about 278.1734378289.

The spelling of 21525189 in words is "twenty-one million, five hundred twenty-five thousand, one hundred eighty-nine".