19915842 has 32 divisors (see below), whose sum is σ = 41182272. Its totient is φ = 6416064.

The previous prime is 19915807. The next prime is 19915849. The reversal of 19915842 is 24851991.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 19915842.

It is not an unprimeable number, because it can be changed into a prime (19915849) 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, 62668 + ... + 62984.

It is an arithmetic number, because the mean of its divisors is an integer number (1286946).

Almost surely, 2^19915842 is an apocalyptic number.

19915842 is an abundant number, since it is smaller than the sum of its proper divisors (21266430).

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

19915842 is a wasteful number, since it uses less digits than its factorization.

19915842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 642.

The product of its digits is 25920, while the sum is 39.

The square root of 19915842 is about 4462.7168854858. The cubic root of 19915842 is about 271.0604931154.

The spelling of 19915842 in words is "nineteen million, nine hundred fifteen thousand, eight hundred forty-two".