1212101220 has 48 divisors (see below), whose sum is σ = 3702420288. Its totient is φ = 293842560.

The previous prime is 1212101201. The next prime is 1212101237. The reversal of 1212101220 is 221012121.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 1212101196 and 1212101205.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 917599 + ... + 918918.

It is an arithmetic number, because the mean of its divisors is an integer number (77133756).

Almost surely, 2^1212101220 is an apocalyptic number.

1212101220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1212101220 is an abundant number, since it is smaller than the sum of its proper divisors (2490319068).

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

1212101220 is a wasteful number, since it uses less digits than its factorization.

1212101220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1836540 (or 1836538 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 1212101220 is about 34815.2440749738. The cubic root of 1212101220 is about 1066.2187023043.

Adding to 1212101220 its reverse (221012121), we get a palindrome (1433113341).

The spelling of 1212101220 in words is "one billion, two hundred twelve million, one hundred one thousand, two hundred twenty".