13887997 has 4 divisors (see below), whose sum is σ = 14704956. Its totient is φ = 13071040.

The previous prime is 13887989. The next prime is 13888001. The reversal of 13887997 is 79978831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79978831 = 7253 ⋅11027.

It can be written as a sum of positive squares in 2 ways, for example, as 8964036 + 4923961 = 2994^2 + 2219^2 .

It is a cyclic number.

It is not a de Polignac number, because 13887997 - 2³ = 13887989 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 (13887977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 408454 + ... + 408487.

It is an arithmetic number, because the mean of its divisors is an integer number (3676239).

Almost surely, 2^13887997 is an apocalyptic number.

13887997 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

13887997 is a deficient number, since it is larger than the sum of its proper divisors (816959).

13887997 is an equidigital number, since it uses as much as digits as its factorization.

13887997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 816958.

The product of its digits is 762048, while the sum is 52.

The square root of 13887997 is about 3726.6603011275. The cubic root of 13887997 is about 240.3697829690.

It can be divided in two parts, 13887 and 997, that added together give a square (14884 = 122²).

The spelling of 13887997 in words is "thirteen million, eight hundred eighty-seven thousand, nine hundred ninety-seven".