21252536530 has 16 divisors (see below), whose sum is σ = 38352913560. Its totient is φ = 8479159552.

The previous prime is 21252536527. The next prime is 21252536537. The reversal of 21252536530 is 3563525212.

It can be written as a sum of positive squares in 4 ways, for example, as 15579283489 + 5673253041 = 124817^2 + 75321^2 .

It is not an unprimeable number, because it can be changed into a prime (21252536537) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2727799 + ... + 2735578.

Almost surely, 2^21252536530 is an apocalyptic number.

21252536530 is a deficient number, since it is larger than the sum of its proper divisors (17100377030).

21252536530 is a wasteful number, since it uses less digits than its factorization.

21252536530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5463773.

The product of its (nonzero) digits is 54000, while the sum is 34.

The spelling of 21252536530 in words is "twenty-one billion, two hundred fifty-two million, five hundred thirty-six thousand, five hundred thirty".