19915000 has 80 divisors (see below), whose sum is σ = 53420400. Its totient is φ = 6816000.

The previous prime is 19914959. The next prime is 19915001. The reversal of 19915000 is 51991.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19915001) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 34716 + ... + 35284.

It is an arithmetic number, because the mean of its divisors is an integer number (667755).

Almost surely, 2^19915000 is an apocalyptic number.

19915000 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 19915000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26710200).

19915000 is an abundant number, since it is smaller than the sum of its proper divisors (33505400).

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

19915000 is an equidigital number, since it uses as much as digits as its factorization.

19915000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 602 (or 583 counting only the distinct ones).

The product of its (nonzero) digits is 405, while the sum is 25.

The square root of 19915000 is about 4462.6225473369. The cubic root of 19915000 is about 271.0566731054.

Adding to 19915000 its reverse (51991), we get a palindrome (19966991).

The spelling of 19915000 in words is "nineteen million, nine hundred fifteen thousand".