19891944 has 24 divisors (see below), whose sum is σ = 53874210. Its totient is φ = 6630624.

The previous prime is 19891939. The next prime is 19891961. The reversal of 19891944 is 44919891.

It can be written as a sum of positive squares in only one way, i.e., 19027044 + 864900 = 4362^2 + 930^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 19891944.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 138067 + ... + 138210.

Almost surely, 2^19891944 is an apocalyptic number.

It is an amenable number.

19891944 is an abundant number, since it is smaller than the sum of its proper divisors (33982266).

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

19891944 is a wasteful number, since it uses less digits than its factorization.

19891944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276289 (or 276282 counting only the distinct ones).

The product of its digits is 93312, while the sum is 45.

The square root of 19891944 is about 4460.0385648557. The cubic root of 19891944 is about 270.9520301072.

The spelling of 19891944 in words is "nineteen million, eight hundred ninety-one thousand, nine hundred forty-four".