21151233530 has 16 divisors (see below), whose sum is σ = 43511109120. Its totient is φ = 7251851472.

The previous prime is 21151233529. The next prime is 21151233533. The reversal of 21151233530 is 3533215112.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21151233530.

It is not an unprimeable number, because it can be changed into a prime (21151233533) 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, 151080170 + ... + 151080309.

It is an arithmetic number, because the mean of its divisors is an integer number (2719444320).

Almost surely, 2^21151233530 is an apocalyptic number.

21151233530 is an abundant number, since it is smaller than the sum of its proper divisors (22359875590).

21151233530 is a wasteful number, since it uses less digits than its factorization.

21151233530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 302160493.

The product of its (nonzero) digits is 2700, while the sum is 26.

Adding to 21151233530 its reverse (3533215112), we get a palindrome (24684448642).

The spelling of 21151233530 in words is "twenty-one billion, one hundred fifty-one million, two hundred thirty-three thousand, five hundred thirty".