19681944 has 32 divisors (see below), whose sum is σ = 49539840. Its totient is φ = 6516000.

The previous prime is 19681943. The next prime is 19681957. The reversal of 19681944 is 44918691.

It is a junction number, because it is equal to n+sod(n) for n = 19681896 and 19681905.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19681943) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 909 + ... + 6339.

It is an arithmetic number, because the mean of its divisors is an integer number (1548120).

Almost surely, 2^19681944 is an apocalyptic number.

It is an amenable number.

19681944 is an abundant number, since it is smaller than the sum of its proper divisors (29857896).

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

19681944 is a wasteful number, since it uses less digits than its factorization.

19681944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5591 (or 5587 counting only the distinct ones).

The product of its digits is 62208, while the sum is 42.

The square root of 19681944 is about 4436.4337028744. The cubic root of 19681944 is about 269.9951713814.

The spelling of 19681944 in words is "nineteen million, six hundred eighty-one thousand, nine hundred forty-four".