21231040451 has 2 divisors, whose sum is σ = 21231040452. Its totient is φ = 21231040450.

The previous prime is 21231040417. The next prime is 21231040471. The reversal of 21231040451 is 15404013212.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21231040451 is a prime.

It is not a weakly prime, because it can be changed into another prime (21231040471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615520225 + 10615520226.

It is an arithmetic number, because the mean of its divisors is an integer number (10615520226).

Almost surely, 2^21231040451 is an apocalyptic number.

21231040451 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231040451 is an equidigital number, since it uses as much as digits as its factorization.

21231040451 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 960, while the sum is 23.

Adding to 21231040451 its reverse (15404013212), we get a palindrome (36635053663).

The spelling of 21231040451 in words is "twenty-one billion, two hundred thirty-one million, forty thousand, four hundred fifty-one".