1211210020 has 12 divisors (see below), whose sum is σ = 2543541084. Its totient is φ = 484484000.

The previous prime is 1211210009. The next prime is 1211210041. The reversal of 1211210020 is 200121121.

It can be written as a sum of positive squares in 2 ways, for example, as 640191204 + 571018816 = 25302^2 + 23896^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 1211209979 and 1211210006.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30280231 + ... + 30280270.

It is an arithmetic number, because the mean of its divisors is an integer number (211961757).

Almost surely, 2^1211210020 is an apocalyptic number.

1211210020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211210020 is an abundant number, since it is smaller than the sum of its proper divisors (1332331064).

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

1211210020 is a wasteful number, since it uses less digits than its factorization.

1211210020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60560510 (or 60560508 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 1211210020 is about 34802.4427303602. The cubic root of 1211210020 is about 1065.9573250449.

Adding to 1211210020 its reverse (200121121), we get a palindrome (1411331141).

The spelling of 1211210020 in words is "one billion, two hundred eleven million, two hundred ten thousand, twenty".