21525069 has 8 divisors (see below), whose sum is σ = 29367712. Its totient is φ = 14016240.

The previous prime is 21525061. The next prime is 21525071. The reversal of 21525069 is 96052512.

It is a happy number.

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

It is not a de Polignac number, because 21525069 - 2³ = 21525061 is a prime.

It is a super-2 number, since 2×21525069² = 926657190909522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21525061) 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, 83302 + ... + 83559.

It is an arithmetic number, because the mean of its divisors is an integer number (3670964).

Almost surely, 2^21525069 is an apocalyptic number.

It is an amenable number.

21525069 is a deficient number, since it is larger than the sum of its proper divisors (7842643).

21525069 is a wasteful number, since it uses less digits than its factorization.

21525069 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166907.

The product of its (nonzero) digits is 5400, while the sum is 30.

The square root of 21525069 is about 4639.5117199981. The cubic root of 21525069 is about 278.1729209015.

It can be divided in two parts, 215 and 25069, that multiplied together give a palindrome (5389835).

The spelling of 21525069 in words is "twenty-one million, five hundred twenty-five thousand, sixty-nine".