1211020220 has 24 divisors (see below), whose sum is σ = 2556465408. Its totient is φ = 481870400.

The previous prime is 1211020207. The next prime is 1211020229. The reversal of 1211020220 is 220201121.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211020229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 154691 + ... + 162330.

It is an arithmetic number, because the mean of its divisors is an integer number (106519392).

Almost surely, 2^1211020220 is an apocalyptic number.

1211020220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211020220 is an abundant number, since it is smaller than the sum of its proper divisors (1345445188).

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

1211020220 is a wasteful number, since it uses less digits than its factorization.

1211020220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 317221 (or 317219 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 1211020220 is about 34799.7158034372. The cubic root of 1211020220 is about 1065.9016426375.

Adding to 1211020220 its reverse (220201121), we get a palindrome (1431221341).

The spelling of 1211020220 in words is "one billion, two hundred eleven million, twenty thousand, two hundred twenty".