19899942 has 16 divisors (see below), whose sum is σ = 40304640. Its totient is φ = 6549192.

The previous prime is 19899889. The next prime is 19899947. The reversal of 19899942 is 24999891.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19899947) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20518 + ... + 21465.

It is an arithmetic number, because the mean of its divisors is an integer number (2519040).

Almost surely, 2^19899942 is an apocalyptic number.

19899942 is an abundant number, since it is smaller than the sum of its proper divisors (20404698).

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

19899942 is a wasteful number, since it uses less digits than its factorization.

19899942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42067.

The product of its digits is 419904, while the sum is 51.

The square root of 19899942 is about 4460.9351037647. The cubic root of 19899942 is about 270.9883393448.

Subtracting from 19899942 its sum of digits (51), we obtain a palindrome (19899891).

The spelling of 19899942 in words is "nineteen million, eight hundred ninety-nine thousand, nine hundred forty-two".