19997700 has 72 divisors (see below), whose sum is σ = 58329600. Its totient is φ = 5289600.

The previous prime is 19997699. The next prime is 19997707. The reversal of 19997700 is 779991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19997707) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 57126 + ... + 57474.

Almost surely, 2^19997700 is an apocalyptic number.

19997700 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 19997700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29164800).

19997700 is an abundant number, since it is smaller than the sum of its proper divisors (38331900).

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

19997700 is a wasteful number, since it uses less digits than its factorization.

19997700 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 557 (or 550 counting only the distinct ones).

The product of its (nonzero) digits is 35721, while the sum is 42.

The square root of 19997700 is about 4471.8787997887. The cubic root of 19997700 is about 271.4313559931.

The spelling of 19997700 in words is "nineteen million, nine hundred ninety-seven thousand, seven hundred".