19971056 has 60 divisors (see below), whose sum is σ = 47052048. Its totient is φ = 8042496.

The previous prime is 19971047. The next prime is 19971101. The reversal of 19971056 is 65017991.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 32060 + ... + 32676.

Almost surely, 2^19971056 is an apocalyptic number.

19971056 is a gapful number since it is divisible by the number (16) 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 19971056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23526024).

19971056 is an abundant number, since it is smaller than the sum of its proper divisors (27080992).

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

19971056 is a wasteful number, since it uses less digits than its factorization.

19971056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 666 (or 643 counting only the distinct ones).

The product of its (nonzero) digits is 17010, while the sum is 38.

The square root of 19971056 is about 4468.8987457762. The cubic root of 19971056 is about 271.3107549357.

The spelling of 19971056 in words is "nineteen million, nine hundred seventy-one thousand, fifty-six".