128821212 has 48 divisors (see below), whose sum is σ = 359675680. Its totient is φ = 39636864.

The previous prime is 128821211. The next prime is 128821247. The reversal of 128821212 is 212128821.

It is a super-2 number, since 2×128821212² = 33189809322297888, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128821211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 44473 + ... + 47280.

Almost surely, 2^128821212 is an apocalyptic number.

128821212 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

128821212 is an abundant number, since it is smaller than the sum of its proper divisors (230854468).

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

128821212 is a wasteful number, since it uses less digits than its factorization.

128821212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91779 (or 91771 counting only the distinct ones).

The product of its digits is 1024, while the sum is 27.

The square root of 128821212 is about 11349.9432597701. The cubic root of 128821212 is about 505.0438964555.

It can be divided in two parts, 1288 and 21212, that added together give a square (22500 = 150²).

The spelling of 128821212 in words is "one hundred twenty-eight million, eight hundred twenty-one thousand, two hundred twelve".