13423991 has 10 divisors (see below), whose sum is σ = 15663192. Its totient is φ = 11504220.

The previous prime is 13423987. The next prime is 13424003. The reversal of 13423991 is 19932431.

It is not a de Polignac number, because 13423991 - 2² = 13423987 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 (13423901) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 395 + ... + 5196.

Almost surely, 2^13423991 is an apocalyptic number.

13423991 is a deficient number, since it is larger than the sum of its proper divisors (2239201).

13423991 is an frugal number, since it uses more digits than its factorization.

13423991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5619 (or 5598 counting only the distinct ones).

The product of its digits is 5832, while the sum is 32.

The square root of 13423991 is about 3663.8764990103. The cubic root of 13423991 is about 237.6624395657.

The spelling of 13423991 in words is "thirteen million, four hundred twenty-three thousand, nine hundred ninety-one".