19987000 has 128 divisors (see below), whose sum is σ = 53913600. Its totient is φ = 6864000.

The previous prime is 19986983. The next prime is 19987001. The reversal of 19987000 is 78991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19987001) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 252961 + ... + 253039.

It is an arithmetic number, because the mean of its divisors is an integer number (421200).

Almost surely, 2^19987000 is an apocalyptic number.

19987000 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 19987000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26956800).

19987000 is an abundant number, since it is smaller than the sum of its proper divisors (33926600).

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

19987000 is a wasteful number, since it uses less digits than its factorization.

19987000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134 (or 120 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 34.

The square root of 19987000 is about 4470.6822745527. The cubic root of 19987000 is about 271.3829365305.

It can be divided in two parts, 1998 and 7000, that added together give a palindrome (8998).

The spelling of 19987000 in words is "nineteen million, nine hundred eighty-seven thousand".