21606642431423 has 32 divisors (see below), whose sum is σ = 26450518579200. Its totient is φ = 17237768907744.

The previous prime is 21606642431393. The next prime is 21606642431449. The reversal of 21606642431423 is 32413424660612.

It is a happy number.

It is not a de Polignac number, because 21606642431423 - 2¹⁶ = 21606642365887 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21606642431123) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 178436 + ... + 6576102.

It is an arithmetic number, because the mean of its divisors is an integer number (826578705600).

Almost surely, 2^{21606642431423} is an apocalyptic number.

21606642431423 is a deficient number, since it is larger than the sum of its proper divisors (4843876147777).

21606642431423 is a wasteful number, since it uses less digits than its factorization.

21606642431423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6398139.

The product of its (nonzero) digits is 995328, while the sum is 44.

The spelling of 21606642431423 in words is "twenty-one trillion, six hundred six billion, six hundred forty-two million, four hundred thirty-one thousand, four hundred twenty-three".