821212212128 has 192 divisors, whose sum is σ = 2038183741440. Its totient is φ = 316396108800.

The previous prime is 821212212077. The next prime is 821212212137.

821212212128 is nontrivially palindromic in base 10.

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

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 821212212094 and 821212212103.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 151205573 + ... + 151211003.

It is an arithmetic number, because the mean of its divisors is an integer number (10615540320).

Almost surely, 2^821212212128 is an apocalyptic number.

821212212128 is a gapful number since it is divisible by the number (88) 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 821212212128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1019091870720).

821212212128 is an abundant number, since it is smaller than the sum of its proper divisors (1216971529312).

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

821212212128 is a wasteful number, since it uses less digits than its factorization.

821212212128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6131 (or 6123 counting only the distinct ones).

The product of its digits is 4096, while the sum is 32.

The spelling of 821212212128 in words is "eight hundred twenty-one billion, two hundred twelve million, two hundred twelve thousand, one hundred twenty-eight".