19910040 has 64 divisors (see below), whose sum is σ = 60480000. Its totient is φ = 5242752.

The previous prime is 19910039. The next prime is 19910053. The reversal of 19910040 is 4001991.

It is a Harshad number since it is a multiple of its sum of digits (24).

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, 8961 + ... + 10959.

It is an arithmetic number, because the mean of its divisors is an integer number (945000).

Almost surely, 2^19910040 is an apocalyptic number.

19910040 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 19910040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30240000).

19910040 is an abundant number, since it is smaller than the sum of its proper divisors (40569960).

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

19910040 is a wasteful number, since it uses less digits than its factorization.

19910040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2096 (or 2092 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 24.

The square root of 19910040 is about 4462.0667856947. The cubic root of 19910040 is about 271.0341682476.

The spelling of 19910040 in words is "nineteen million, nine hundred ten thousand, forty".