21233204251 has 12 divisors (see below), whose sum is σ = 24926460240. Its totient is φ = 18032913360.

The previous prime is 21233204249. The next prime is 21233204327. The reversal of 21233204251 is 15240233212.

It is not a de Polignac number, because 21233204251 - 2¹ = 21233204249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21233204351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1982415 + ... + 1993096.

It is an arithmetic number, because the mean of its divisors is an integer number (2077205020).

Almost surely, 2^21233204251 is an apocalyptic number.

21233204251 is a deficient number, since it is larger than the sum of its proper divisors (3693255989).

21233204251 is a wasteful number, since it uses less digits than its factorization.

21233204251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3975634 (or 3975627 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 25.

Adding to 21233204251 its reverse (15240233212), we get a palindrome (36473437463).

The spelling of 21233204251 in words is "twenty-one billion, two hundred thirty-three million, two hundred four thousand, two hundred fifty-one".