19999240 has 32 divisors (see below), whose sum is σ = 46217880. Its totient is φ = 7782912.

The previous prime is 19999237. The next prime is 19999249. The reversal of 19999240 is 4299991.

It can be written as a sum of positive squares in 4 ways, for example, as 19027044 + 972196 = 4362^2 + 986^2 .

It is not an unprimeable number, because it can be changed into a prime (19999249) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5277 + ... + 8236.

Almost surely, 2^19999240 is an apocalyptic number.

19999240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19999240 is an abundant number, since it is smaller than the sum of its proper divisors (26218640).

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

19999240 is a wasteful number, since it uses less digits than its factorization.

19999240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13561 (or 13557 counting only the distinct ones).

The product of its (nonzero) digits is 52488, while the sum is 43.

The square root of 19999240 is about 4472.0509836092. The cubic root of 19999240 is about 271.4383233536.

The spelling of 19999240 in words is "nineteen million, nine hundred ninety-nine thousand, two hundred forty".