19867842 has 40 divisors (see below), whose sum is σ = 46064700. Its totient is φ = 6392736.

The previous prime is 19867819. The next prime is 19867847. The reversal of 19867842 is 24876891.

It can be written as a sum of positive squares in 2 ways, for example, as 17214201 + 2653641 = 4149^2 + 1629^2 .

It is a super-2 number, since 2×19867842² = 789462291473928, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (19867847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2584 + ... + 6812.

Almost surely, 2^19867842 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19867842, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23032350).

19867842 is an abundant number, since it is smaller than the sum of its proper divisors (26196858).

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

19867842 is a wasteful number, since it uses less digits than its factorization.

19867842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4272 (or 4263 counting only the distinct ones).

The product of its digits is 193536, while the sum is 45.

The square root of 19867842 is about 4457.3357513205. The cubic root of 19867842 is about 270.8425532062.

The spelling of 19867842 in words is "nineteen million, eight hundred sixty-seven thousand, eight hundred forty-two".