21234432253 has 2 divisors, whose sum is σ = 21234432254. Its totient is φ = 21234432252.

The previous prime is 21234432251. The next prime is 21234432299. The reversal of 21234432253 is 35223443212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20312520484 + 921911769 = 142522^2 + 30363^2 .

It is a cyclic number.

It is not a de Polignac number, because 21234432253 - 2¹ = 21234432251 is a prime.

It is a super-2 number, since 2×21234432253² (a number of 21 digits) contains 22 as substring.

Together with 21234432251, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21234432251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10617216126 + 10617216127.

It is an arithmetic number, because the mean of its divisors is an integer number (10617216127).

Almost surely, 2^21234432253 is an apocalyptic number.

It is an amenable number.

21234432253 is a deficient number, since it is larger than the sum of its proper divisors (1).

21234432253 is an equidigital number, since it uses as much as digits as its factorization.

21234432253 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34560, while the sum is 31.

Adding to 21234432253 its reverse (35223443212), we get a palindrome (56457875465).

The spelling of 21234432253 in words is "twenty-one billion, two hundred thirty-four million, four hundred thirty-two thousand, two hundred fifty-three".