21658138423 has 2 divisors, whose sum is σ = 21658138424. Its totient is φ = 21658138422.

The previous prime is 21658138409. The next prime is 21658138451. The reversal of 21658138423 is 32483185612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21658138423 - 2¹³ = 21658130231 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21658138423.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21658138223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10829069211 + 10829069212.

It is an arithmetic number, because the mean of its divisors is an integer number (10829069212).

Almost surely, 2^21658138423 is an apocalyptic number.

21658138423 is a deficient number, since it is larger than the sum of its proper divisors (1).

21658138423 is an equidigital number, since it uses as much as digits as its factorization.

21658138423 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 276480, while the sum is 43.

The spelling of 21658138423 in words is "twenty-one billion, six hundred fifty-eight million, one hundred thirty-eight thousand, four hundred twenty-three".