21131402423 has 2 divisors, whose sum is σ = 21131402424. Its totient is φ = 21131402422.

The previous prime is 21131402401. The next prime is 21131402437. The reversal of 21131402423 is 32420413112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21131402423 - 2¹⁶ = 21131336887 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21131402473) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10565701211 + 10565701212.

It is an arithmetic number, because the mean of its divisors is an integer number (10565701212).

Almost surely, 2^21131402423 is an apocalyptic number.

21131402423 is a deficient number, since it is larger than the sum of its proper divisors (1).

21131402423 is an equidigital number, since it uses as much as digits as its factorization.

21131402423 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 23.

Adding to 21131402423 its reverse (32420413112), we get a palindrome (53551815535).

The spelling of 21131402423 in words is "twenty-one billion, one hundred thirty-one million, four hundred two thousand, four hundred twenty-three".