21971672080 has 80 divisors (see below), whose sum is σ = 51817062960. Its totient is φ = 8663187456.

The previous prime is 21971672069. The next prime is 21971672111. The reversal of 21971672080 is 8027617912.

It can be written as a sum of positive squares in 8 ways, for example, as 6267572224 + 15704099856 = 79168^2 + 125316^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2394862 + ... + 2404018.

It is an arithmetic number, because the mean of its divisors is an integer number (647713287).

Almost surely, 2^21971672080 is an apocalyptic number.

21971672080 is a gapful number since it is divisible by the number (20) 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 21971672080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25908531480).

21971672080 is an abundant number, since it is smaller than the sum of its proper divisors (29845390880).

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

21971672080 is a wasteful number, since it uses less digits than its factorization.

21971672080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9596 (or 9590 counting only the distinct ones).

The product of its (nonzero) digits is 84672, while the sum is 43.

The spelling of 21971672080 in words is "twenty-one billion, nine hundred seventy-one million, six hundred seventy-two thousand, eighty".