212121028 has 24 divisors (see below), whose sum is σ = 426853952. Its totient is φ = 90349344.

The previous prime is 212121023. The next prime is 212121029. The reversal of 212121028 is 820121212.

It is a super-3 number, since 3×212121028³ (a number of 26 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 212120996 and 212121014.

It is not an unprimeable number, because it can be changed into a prime (212121023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18675 + ... + 27802.

Almost surely, 2^212121028 is an apocalyptic number.

212121028 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

212121028 is an abundant number, since it is smaller than the sum of its proper divisors (214732924).

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

212121028 is a wasteful number, since it uses less digits than its factorization.

212121028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46651 (or 46649 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

The square root of 212121028 is about 14564.3753041454. The cubic root of 212121028 is about 596.3866423528.

The spelling of 212121028 in words is "two hundred twelve million, one hundred twenty-one thousand, twenty-eight".