19997056 has 16 divisors (see below), whose sum is σ = 39838140. Its totient is φ = 9998464.

The previous prime is 19997041. The next prime is 19997069. The reversal of 19997056 is 65079991.

It is a tau number, because it is divible by the number of its divisors (16).

It is a junction number, because it is equal to n+sod(n) for n = 19996997 and 19997015.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 77986 + ... + 78241.

Almost surely, 2^19997056 is an apocalyptic number.

19997056 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

19997056 is a deficient number, since it is larger than the sum of its proper divisors (19841084).

19997056 is an equidigital number, since it uses as much as digits as its factorization.

19997056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156241 (or 156229 counting only the distinct ones).

The product of its (nonzero) digits is 153090, while the sum is 46.

The square root of 19997056 is about 4471.8067936797. The cubic root of 19997056 is about 271.4284422635.

The spelling of 19997056 in words is "nineteen million, nine hundred ninety-seven thousand, fifty-six".