21275557312 has 56 divisors (see below), whose sum is σ = 43339816800. Its totient is φ = 10356387840.

The previous prime is 21275557297. The next prime is 21275557367. The reversal of 21275557312 is 21375557212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1269564 + ... + 1286212.

It is an arithmetic number, because the mean of its divisors is an integer number (773925300).

Almost surely, 2^21275557312 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21275557312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21669908400).

21275557312 is an abundant number, since it is smaller than the sum of its proper divisors (22064259488).

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

21275557312 is a wasteful number, since it uses less digits than its factorization.

21275557312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17189 (or 17179 counting only the distinct ones).

The product of its digits is 147000, while the sum is 40.

The spelling of 21275557312 in words is "twenty-one billion, two hundred seventy-five million, five hundred fifty-seven thousand, three hundred twelve".