21525433 has 4 divisors (see below), whose sum is σ = 21575808. Its totient is φ = 21475060.

The previous prime is 21525419. The next prime is 21525463. The reversal of 21525433 is 33452512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21525433 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21525398 and 21525407.

It is not an unprimeable number, because it can be changed into a prime (21525403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24541 + ... + 25402.

It is an arithmetic number, because the mean of its divisors is an integer number (5393952).

Almost surely, 2^21525433 is an apocalyptic number.

It is an amenable number.

21525433 is a deficient number, since it is larger than the sum of its proper divisors (50375).

21525433 is an equidigital number, since it uses as much as digits as its factorization.

21525433 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50374.

The product of its digits is 3600, while the sum is 25.

The square root of 21525433 is about 4639.5509480983. The cubic root of 21525433 is about 278.1744889085.

Adding to 21525433 its reverse (33452512), we get a palindrome (54977945).

The spelling of 21525433 in words is "twenty-one million, five hundred twenty-five thousand, four hundred thirty-three".