13987890 has 80 divisors (see below), whose sum is σ = 43002432. Its totient is φ = 3195936.

The previous prime is 13987877. The next prime is 13987891. The reversal of 13987890 is 9878931.

It is a super-2 number, since 2×13987890² = 391322133304200, which contains 22 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (13987891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 4437 + ... + 6903.

Almost surely, 2^13987890 is an apocalyptic number.

13987890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 13987890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21501216).

13987890 is an abundant number, since it is smaller than the sum of its proper divisors (29014542).

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

13987890 is a wasteful number, since it uses less digits than its factorization.

13987890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2493 (or 2484 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 45.

The square root of 13987890 is about 3740.0387698525. The cubic root of 13987890 is about 240.9447139356.

The spelling of 13987890 in words is "thirteen million, nine hundred eighty-seven thousand, eight hundred ninety".