1211102220 has 48 divisors (see below), whose sum is σ = 3404324448. Its totient is φ = 321699840.

The previous prime is 1211102183. The next prime is 1211102257. The reversal of 1211102220 is 222011121.

It is an interprime number because it is at equal distance from previous prime (1211102183) and next prime (1211102257).

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 = 1211102196 and 1211102205.

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, 23851 + ... + 54690.

It is an arithmetic number, because the mean of its divisors is an integer number (70923426).

Almost surely, 2^1211102220 is an apocalyptic number.

1211102220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211102220 is an abundant number, since it is smaller than the sum of its proper divisors (2193222228).

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

1211102220 is a wasteful number, since it uses less digits than its factorization.

1211102220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78810 (or 78808 counting only the distinct ones).

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

The square root of 1211102220 is about 34800.8939540351. The cubic root of 1211102220 is about 1065.9257000288.

Adding to 1211102220 its reverse (222011121), we get a palindrome (1433113341).

The spelling of 1211102220 in words is "one billion, two hundred eleven million, one hundred two thousand, two hundred twenty".