19971423 has 12 divisors (see below), whose sum is σ = 28955368. Its totient is φ = 13264560.

The previous prime is 19971421. The next prime is 19971433. The reversal of 19971423 is 32417991.

It is not a de Polignac number, because 19971423 - 2¹ = 19971421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19971421) 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, 1513 + ... + 6498.

Almost surely, 2^19971423 is an apocalyptic number.

19971423 is a deficient number, since it is larger than the sum of its proper divisors (8983945).

19971423 is a wasteful number, since it uses less digits than its factorization.

19971423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8294 (or 8291 counting only the distinct ones).

The product of its digits is 13608, while the sum is 36.

The square root of 19971423 is about 4468.9398071578. The cubic root of 19971423 is about 271.3124168481.

The spelling of 19971423 in words is "nineteen million, nine hundred seventy-one thousand, four hundred twenty-three".