21335540423 has 2 divisors, whose sum is σ = 21335540424. Its totient is φ = 21335540422.

The previous prime is 21335540417. The next prime is 21335540441. The reversal of 21335540423 is 32404553312.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21335540423 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21335540423.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21335540123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10667770211 + 10667770212.

It is an arithmetic number, because the mean of its divisors is an integer number (10667770212).

Almost surely, 2^21335540423 is an apocalyptic number.

21335540423 is a deficient number, since it is larger than the sum of its proper divisors (1).

21335540423 is an equidigital number, since it uses as much as digits as its factorization.

21335540423 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 43200, while the sum is 32.

The spelling of 21335540423 in words is "twenty-one billion, three hundred thirty-five million, five hundred forty thousand, four hundred twenty-three".