21524249 has 2 divisors, whose sum is σ = 21524250. Its totient is φ = 21524248.

The previous prime is 21524231. The next prime is 21524263. The reversal of 21524249 is 94242512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17280649 + 4243600 = 4157^2 + 2060^2 .

It is a cyclic number.

It is not a de Polignac number, because 21524249 - 2²⁴ = 4747033 is a prime.

It is not a weakly prime, because it can be changed into another prime (21524299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10762124 + 10762125.

It is an arithmetic number, because the mean of its divisors is an integer number (10762125).

Almost surely, 2^21524249 is an apocalyptic number.

It is an amenable number.

21524249 is a deficient number, since it is larger than the sum of its proper divisors (1).

21524249 is an equidigital number, since it uses as much as digits as its factorization.

21524249 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5760, while the sum is 29.

The square root of 21524249 is about 4639.4233477880. The cubic root of 21524249 is about 278.1693885135.

It can be divided in two parts, 2 and 1524249, that added together give a palindrome (1524251).

The spelling of 21524249 in words is "twenty-one million, five hundred twenty-four thousand, two hundred forty-nine".