1211013220 has 48 divisors (see below), whose sum is σ = 2572113600. Its totient is φ = 478917504.

The previous prime is 1211013161. The next prime is 1211013259. The reversal of 1211013220 is 223101121.

It is a self number, because there is not a number n which added to its sum of digits gives 1211013220.

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, 711931 + ... + 713629.

It is an arithmetic number, because the mean of its divisors is an integer number (53585700).

Almost surely, 2^1211013220 is an apocalyptic number.

1211013220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211013220 is an abundant number, since it is smaller than the sum of its proper divisors (1361100380).

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

1211013220 is a wasteful number, since it uses less digits than its factorization.

1211013220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2092 (or 2090 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 1211013220 is about 34799.6152277579. The cubic root of 1211013220 is about 1065.8995889074.

Adding to 1211013220 its reverse (223101121), we get a palindrome (1434114341).

The spelling of 1211013220 in words is "one billion, two hundred eleven million, thirteen thousand, two hundred twenty".