19910140 has 48 divisors (see below), whose sum is σ = 43545600. Its totient is φ = 7641152.

The previous prime is 19910113. The next prime is 19910141. The reversal of 19910140 is 4101991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19910141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55281 + ... + 55639.

It is an arithmetic number, because the mean of its divisors is an integer number (907200).

Almost surely, 2^19910140 is an apocalyptic number.

19910140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19910140 is an abundant number, since it is smaller than the sum of its proper divisors (23635460).

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

19910140 is a wasteful number, since it uses less digits than its factorization.

19910140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 474 (or 472 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 25.

The square root of 19910140 is about 4462.0779912503. The cubic root of 19910140 is about 271.0346220114.

The spelling of 19910140 in words is "nineteen million, nine hundred ten thousand, one hundred forty".