21525053 has 6 divisors (see below), whose sum is σ = 23659902. Its totient is φ = 19568120.

The previous prime is 21525017. The next prime is 21525059. The reversal of 21525053 is 35052512.

It can be written as a sum of positive squares in only one way, i.e., 15507844 + 6017209 = 3938^2 + 2453^2 .

It is not a de Polignac number, because 21525053 - 2¹⁰ = 21524029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21525059) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 88826 + ... + 89067.

It is an arithmetic number, because the mean of its divisors is an integer number (3943317).

Almost surely, 2^21525053 is an apocalyptic number.

It is an amenable number.

21525053 is a deficient number, since it is larger than the sum of its proper divisors (2134849).

21525053 is a wasteful number, since it uses less digits than its factorization.

21525053 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177915 (or 177904 counting only the distinct ones).

The product of its (nonzero) digits is 1500, while the sum is 23.

The square root of 21525053 is about 4639.5099956784. The cubic root of 21525053 is about 278.1728519777.

Adding to 21525053 its reverse (35052512), we get a palindrome (56577565).

The spelling of 21525053 in words is "twenty-one million, five hundred twenty-five thousand, fifty-three".