19997568 has 48 divisors (see below), whose sum is σ = 57548400. Its totient is φ = 6665472.

The previous prime is 19997567. The next prime is 19997581. The reversal of 19997568 is 86579991.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19997563) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7528 + ... + 9831.

It is an arithmetic number, because the mean of its divisors is an integer number (1198925).

Almost surely, 2^19997568 is an apocalyptic number.

19997568 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

19997568 is an abundant number, since it is smaller than the sum of its proper divisors (37550832).

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

19997568 is a wasteful number, since it uses less digits than its factorization.

19997568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17379 (or 17364 counting only the distinct ones).

The product of its digits is 1224720, while the sum is 54.

The square root of 19997568 is about 4471.8640408671. The cubic root of 19997568 is about 271.4307587741.

The spelling of 19997568 in words is "nineteen million, nine hundred ninety-seven thousand, five hundred sixty-eight".