19813940 has 24 divisors (see below), whose sum is σ = 41785632. Its totient is φ = 7892000.

The previous prime is 19813933. The next prime is 19813943. The reversal of 19813940 is 4931891.

It is a super-3 number, since 3×19813940³ (a number of 23 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 19813940.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19813943) 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, 3047 + ... + 6993.

It is an arithmetic number, because the mean of its divisors is an integer number (1741068).

Almost surely, 2^19813940 is an apocalyptic number.

19813940 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19813940 is an abundant number, since it is smaller than the sum of its proper divisors (21971692).

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

19813940 is a wasteful number, since it uses less digits than its factorization.

19813940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4207 (or 4205 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 19813940 is about 4451.2852076676. The cubic root of 19813940 is about 270.5973969432.

The spelling of 19813940 in words is "nineteen million, eight hundred thirteen thousand, nine hundred forty".