19871040 has 112 divisors (see below), whose sum is σ = 72127872. Its totient is φ = 4540416.

The previous prime is 19871039. The next prime is 19871051. The reversal of 19871040 is 4017891.

It is a tau number, because it is divible by the number of its divisors (112).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 19870989 and 19871007.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 5242 + ... + 8198.

Almost surely, 2^19871040 is an apocalyptic number.

19871040 is a gapful number since it is divisible by the number (10) 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 19871040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36063936).

19871040 is an abundant number, since it is smaller than the sum of its proper divisors (52256832).

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

19871040 is a wasteful number, since it uses less digits than its factorization.

19871040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2984 (or 2974 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 19871040 is about 4457.6944713607. The cubic root of 19871040 is about 270.8570843602.

The spelling of 19871040 in words is "nineteen million, eight hundred seventy-one thousand, forty".