13997988 has 96 divisors (see below), whose sum is σ = 38814720. Its totient is φ = 4354560.

The previous prime is 13997983. The next prime is 13997993. The reversal of 13997988 is 88979931.

It is an interprime number because it is at equal distance from previous prime (13997983) and next prime (13997993).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (13997983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 123820 + ... + 123932.

It is an arithmetic number, because the mean of its divisors is an integer number (404320).

Almost surely, 2^13997988 is an apocalyptic number.

13997988 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 13997988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19407360).

13997988 is an abundant number, since it is smaller than the sum of its proper divisors (24816732).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

13997988 is a wasteful number, since it uses less digits than its factorization.

13997988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194 (or 186 counting only the distinct ones).

The product of its digits is 979776, while the sum is 54.

The square root of 13997988 is about 3741.3885123040. The cubic root of 13997988 is about 241.0026801353.

It can be divided in two parts, 13 and 997988, that added together give a square (998001 = 999²).

The spelling of 13997988 in words is "thirteen million, nine hundred ninety-seven thousand, nine hundred eighty-eight".