1971099648 has 144 divisors (see below), whose sum is σ = 6506594640. Its totient is φ = 563134464.

The previous prime is 1971099619. The next prime is 1971099719. The reversal of 1971099648 is 8469901791.

It is a tau number, because it is divible by the number of its divisors (144).

It is a junction number, because it is equal to n+sod(n) for n = 1971099594 and 1971099603.

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, 121386 + ... + 136662.

It is an arithmetic number, because the mean of its divisors is an integer number (45184685).

Almost surely, 2^1971099648 is an apocalyptic number.

1971099648 is a gapful number since it is divisible by the number (18) 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 1971099648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3253297320).

1971099648 is an abundant number, since it is smaller than the sum of its proper divisors (4535494992).

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

1971099648 is a wasteful number, since it uses less digits than its factorization.

1971099648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15312 (or 15289 counting only the distinct ones).

The product of its (nonzero) digits is 979776, while the sum is 54.

The square root of 1971099648 is about 44397.0680113000. The cubic root of 1971099648 is about 1253.8228880759.

The spelling of 1971099648 in words is "one billion, nine hundred seventy-one million, ninety-nine thousand, six hundred forty-eight".