19997040 has 80 divisors (see below), whose sum is σ = 70852608. Its totient is φ = 4570368.

The previous prime is 19997027. The next prime is 19997041. The reversal of 19997040 is 4079991.

It is a tau number, because it is divible by the number of its divisors (80).

It is a self number, because there is not a number n which added to its sum of digits gives 19997040.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19997041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4272 + ... + 7631.

Almost surely, 2^19997040 is an apocalyptic number.

19997040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19997040 is an abundant number, since it is smaller than the sum of its proper divisors (50855568).

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

19997040 is a wasteful number, since it uses less digits than its factorization.

19997040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11926 (or 11920 counting only the distinct ones).

The product of its (nonzero) digits is 20412, while the sum is 39.

The square root of 19997040 is about 4471.8050046933. The cubic root of 19997040 is about 271.4283698719.

The spelling of 19997040 in words is "nineteen million, nine hundred ninety-seven thousand, forty".