1221025212 has 48 divisors (see below), whose sum is σ = 3453408000. Its totient is φ = 370007280.

The previous prime is 1221025171. The next prime is 1221025217. The reversal of 1221025212 is 2125201221.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221025217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 512712 + ... + 515087.

It is an arithmetic number, because the mean of its divisors is an integer number (71946000).

Almost surely, 2^1221025212 is an apocalyptic number.

1221025212 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1221025212 is an abundant number, since it is smaller than the sum of its proper divisors (2232382788).

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

1221025212 is a wasteful number, since it uses less digits than its factorization.

1221025212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1027823 (or 1027815 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 1221025212 is about 34943.1711783576. The cubic root of 1221025212 is about 1068.8289549549.

Adding to 1221025212 its reverse (2125201221), we get a palindrome (3346226433).

The spelling of 1221025212 in words is "one billion, two hundred twenty-one million, twenty-five thousand, two hundred twelve".