21440368423 has 2 divisors, whose sum is σ = 21440368424. Its totient is φ = 21440368422.

The previous prime is 21440368399. The next prime is 21440368529. The reversal of 21440368423 is 32486304412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21440368423 - 2²¹ = 21438271271 is a prime.

It is a super-2 number, since 2×21440368423² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21440368823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10720184211 + 10720184212.

It is an arithmetic number, because the mean of its divisors is an integer number (10720184212).

Almost surely, 2^21440368423 is an apocalyptic number.

21440368423 is a deficient number, since it is larger than the sum of its proper divisors (1).

21440368423 is an equidigital number, since it uses as much as digits as its factorization.

21440368423 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 110592, while the sum is 37.

The spelling of 21440368423 in words is "twenty-one billion, four hundred forty million, three hundred sixty-eight thousand, four hundred twenty-three".