21231435451 has 2 divisors, whose sum is σ = 21231435452. Its totient is φ = 21231435450.

The previous prime is 21231435419. The next prime is 21231435469. The reversal of 21231435451 is 15453413212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21231435451 - 2⁵ = 21231435419 is a prime.

It is not a weakly prime, because it can be changed into another prime (21231435151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615717725 + 10615717726.

It is an arithmetic number, because the mean of its divisors is an integer number (10615717726).

Almost surely, 2^21231435451 is an apocalyptic number.

21231435451 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231435451 is an equidigital number, since it uses as much as digits as its factorization.

21231435451 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14400, while the sum is 31.

Adding to 21231435451 its reverse (15453413212), we get a palindrome (36684848663).

The spelling of 21231435451 in words is "twenty-one billion, two hundred thirty-one million, four hundred thirty-five thousand, four hundred fifty-one".