211515312128 has 96 divisors (see below), whose sum is σ = 448624121400. Its totient is φ = 99354673152.

The previous prime is 211515312061. The next prime is 211515312157. The reversal of 211515312128 is 821213515112.

It can be written as a sum of positive squares in 4 ways, for example, as 196171039744 + 15344272384 = 442912^2 + 123872^2 .

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 211515312094 and 211515312103.

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, 20083568 + ... + 20094096.

Almost surely, 2^211515312128 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 211515312128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (224312060700).

211515312128 is an abundant number, since it is smaller than the sum of its proper divisors (237108809272).

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

211515312128 is a wasteful number, since it uses less digits than its factorization.

211515312128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11145 (or 11125 counting only the distinct ones).

The product of its digits is 4800, while the sum is 32.

The spelling of 211515312128 in words is "two hundred eleven billion, five hundred fifteen million, three hundred twelve thousand, one hundred twenty-eight".