19871680 has 28 divisors (see below), whose sum is σ = 47320200. Its totient is φ = 7948544.

The previous prime is 19871659. The next prime is 19871689. The reversal of 19871680 is 8617891.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19871689) 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 3 ways as a sum of consecutive naturals, for example, 30730 + ... + 31369.

Almost surely, 2^19871680 is an apocalyptic number.

19871680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19871680 is an abundant number, since it is smaller than the sum of its proper divisors (27448520).

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

19871680 is an equidigital number, since it uses as much as digits as its factorization.

19871680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62116 (or 62106 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 40.

The square root of 19871680 is about 4457.7662567703. The cubic root of 19871680 is about 270.8599922213.

The spelling of 19871680 in words is "nineteen million, eight hundred seventy-one thousand, six hundred eighty".