21010213423 has 2 divisors, whose sum is σ = 21010213424. Its totient is φ = 21010213422.

The previous prime is 21010213379. The next prime is 21010213481. The reversal of 21010213423 is 32431201012.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21010213423 - 2⁹ = 21010212911 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21010213423.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21010213223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505106711 + 10505106712.

It is an arithmetic number, because the mean of its divisors is an integer number (10505106712).

Almost surely, 2^21010213423 is an apocalyptic number.

21010213423 is a deficient number, since it is larger than the sum of its proper divisors (1).

21010213423 is an equidigital number, since it uses as much as digits as its factorization.

21010213423 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21010213423 its reverse (32431201012), we get a palindrome (53441414435).

The spelling of 21010213423 in words is "twenty-one billion, ten million, two hundred thirteen thousand, four hundred twenty-three".