21271332576 has 96 divisors (see below), whose sum is σ = 60716597760. Its totient is φ = 6481442304.

The previous prime is 21271332559. The next prime is 21271332601. The reversal of 21271332576 is 67523317212.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

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, 45805 + ... + 211283.

It is an arithmetic number, because the mean of its divisors is an integer number (632464560).

Almost surely, 2^21271332576 is an apocalyptic number.

21271332576 is a gapful number since it is divisible by the number (26) 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 21271332576, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30358298880).

21271332576 is an abundant number, since it is smaller than the sum of its proper divisors (39445265184).

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

21271332576 is a wasteful number, since it uses less digits than its factorization.

21271332576 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165608 (or 165600 counting only the distinct ones).

The product of its digits is 105840, while the sum is 39.

Adding to 21271332576 its reverse (67523317212), we get a palindrome (88794649788).

The spelling of 21271332576 in words is "twenty-one billion, two hundred seventy-one million, three hundred thirty-two thousand, five hundred seventy-six".