19687680 has 108 divisors (see below), whose sum is σ = 68157180. Its totient is φ = 5246976.

The previous prime is 19687639. The next prime is 19687693. The reversal of 19687680 is 8678691.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 5308416 + 14379264 = 2304^2 + 3792^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10666 + ... + 12374.

It is an arithmetic number, because the mean of its divisors is an integer number (631085).

Almost surely, 2^19687680 is an apocalyptic number.

19687680 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 19687680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34078590).

19687680 is an abundant number, since it is smaller than the sum of its proper divisors (48469500).

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

19687680 is a wasteful number, since it uses less digits than its factorization.

19687680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1736 (or 1719 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 19687680 is about 4437.0801209805. The cubic root of 19687680 is about 270.0213974812.

The spelling of 19687680 in words is "nineteen million, six hundred eighty-seven thousand, six hundred eighty".