19999120 has 20 divisors (see below), whose sum is σ = 46498140. Its totient is φ = 7999616.

The previous prime is 19999117. The next prime is 19999127. The reversal of 19999120 is 2199991.

It can be written as a sum of positive squares in 2 ways, for example, as 6071296 + 13927824 = 2464^2 + 3732^2 .

It is a tau number, because it is divible by the number of its divisors (20).

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

It is not an unprimeable number, because it can be changed into a prime (19999127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 124915 + ... + 125074.

It is an arithmetic number, because the mean of its divisors is an integer number (2324907).

Almost surely, 2^19999120 is an apocalyptic number.

19999120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19999120 is an abundant number, since it is smaller than the sum of its proper divisors (26499020).

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

19999120 is a wasteful number, since it uses less digits than its factorization.

19999120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 250002 (or 249996 counting only the distinct ones).

The product of its (nonzero) digits is 13122, while the sum is 40.

The square root of 19999120 is about 4472.0375669263. The cubic root of 19999120 is about 271.4377804553.

The spelling of 19999120 in words is "nineteen million, nine hundred ninety-nine thousand, one hundred twenty".