19913838 has 32 divisors (see below), whose sum is σ = 45722880. Its totient is φ = 5664000.

The previous prime is 19913779. The next prime is 19913863. The reversal of 19913838 is 83831991.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 19913838.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9598 + ... + 11486.

It is an arithmetic number, because the mean of its divisors is an integer number (1428840).

Almost surely, 2^19913838 is an apocalyptic number.

19913838 is an abundant number, since it is smaller than the sum of its proper divisors (25809042).

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

19913838 is a wasteful number, since it uses less digits than its factorization.

19913838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2152.

The product of its digits is 46656, while the sum is 42.

The square root of 19913838 is about 4462.4923529346. The cubic root of 19913838 is about 271.0514011331.

The spelling of 19913838 in words is "nineteen million, nine hundred thirteen thousand, eight hundred thirty-eight".