21403234451 has 2 divisors, whose sum is σ = 21403234452. Its totient is φ = 21403234450.

The previous prime is 21403234423. The next prime is 21403234459. The reversal of 21403234451 is 15443230412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21403234451 - 2²² = 21399040147 is a prime.

It is not a weakly prime, because it can be changed into another prime (21403234459) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10701617225 + 10701617226.

It is an arithmetic number, because the mean of its divisors is an integer number (10701617226).

Almost surely, 2^21403234451 is an apocalyptic number.

21403234451 is a deficient number, since it is larger than the sum of its proper divisors (1).

21403234451 is an equidigital number, since it uses as much as digits as its factorization.

21403234451 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11520, while the sum is 29.

Adding to 21403234451 its reverse (15443230412), we get a palindrome (36846464863).

The spelling of 21403234451 in words is "twenty-one billion, four hundred three million, two hundred thirty-four thousand, four hundred fifty-one".