19923840 has 128 divisors (see below), whose sum is σ = 70624800. Its totient is φ = 5308416.

The previous prime is 19923823. The next prime is 19923851. The reversal of 19923840 is 4832991.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 19923795 and 19923804.

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, 16704 + ... + 17856.

Almost surely, 2^19923840 is an apocalyptic number.

19923840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19923840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35312400).

19923840 is an abundant number, since it is smaller than the sum of its proper divisors (50700960).

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

19923840 is a wasteful number, since it uses less digits than its factorization.

19923840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1181 (or 1163 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 19923840 is about 4463.6128864408. The cubic root of 19923840 is about 271.0967733069.

It can be divided in two parts, 1992 and 3840, that added together give a cube (5832 = 18³).

The spelling of 19923840 in words is "nineteen million, nine hundred twenty-three thousand, eight hundred forty".