19999280 has 80 divisors (see below), whose sum is σ = 53996544. Its totient is φ = 6746880.

The previous prime is 19999261. The next prime is 19999283. The reversal of 19999280 is 8299991.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (19999283) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39509 + ... + 40011.

Almost surely, 2^19999280 is an apocalyptic number.

19999280 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 19999280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26998272).

19999280 is an abundant number, since it is smaller than the sum of its proper divisors (33997264).

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

19999280 is a wasteful number, since it uses less digits than its factorization.

19999280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 594 (or 588 counting only the distinct ones).

The product of its (nonzero) digits is 104976, while the sum is 47.

The square root of 19999280 is about 4472.0554558279. The cubic root of 19999280 is about 271.4385043193.

The spelling of 19999280 in words is "nineteen million, nine hundred ninety-nine thousand, two hundred eighty".