1212122220 has 48 divisors (see below), whose sum is σ = 3485676768. Its totient is φ = 314496000.

The previous prime is 1212122213. The next prime is 1212122269. The reversal of 1212122220 is 222212121.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 1212122220.

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, 270781 + ... + 275220.

It is an arithmetic number, because the mean of its divisors is an integer number (72618266).

Almost surely, 2^1212122220 is an apocalyptic number.

1212122220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1212122220 is an abundant number, since it is smaller than the sum of its proper divisors (2273554548).

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

1212122220 is a wasteful number, since it uses less digits than its factorization.

1212122220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 546050 (or 546048 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 1212122220 is about 34815.5456656937. The cubic root of 1212122220 is about 1066.2248597833.

Adding to 1212122220 its reverse (222212121), we get a palindrome (1434334341).

The spelling of 1212122220 in words is "one billion, two hundred twelve million, one hundred twenty-two thousand, two hundred twenty".