21999186423 has 12 divisors (see below), whose sum is σ = 33449055640. Its totient is φ = 13894222896.

The previous prime is 21999186421. The next prime is 21999186431. The reversal of 21999186423 is 32468199912.

It is not a de Polignac number, because 21999186423 - 2¹ = 21999186421 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21999186423.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21999186421) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 64324936 + ... + 64325277.

Almost surely, 2^21999186423 is an apocalyptic number.

21999186423 is a deficient number, since it is larger than the sum of its proper divisors (11449869217).

21999186423 is a wasteful number, since it uses less digits than its factorization.

21999186423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128650238 (or 128650235 counting only the distinct ones).

The product of its digits is 1679616, while the sum is 54.

The spelling of 21999186423 in words is "twenty-one billion, nine hundred ninety-nine million, one hundred eighty-six thousand, four hundred twenty-three".