1011211209 has 14 divisors (see below), whose sum is σ = 1516124346. Its totient is φ = 674140320.

The previous prime is 1011211193. The next prime is 1011211231. The reversal of 1011211209 is 9021121101.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 825297984 + 185913225 = 28728^2 + 13635^2 .

It is not a de Polignac number, because 1011211209 - 2⁴ = 1011211193 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1011211191 and 1011211200.

It is not an unprimeable number, because it can be changed into a prime (1011211709) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 692832 + ... + 694289.

Almost surely, 2^1011211209 is an apocalyptic number.

It is an amenable number.

1011211209 is a deficient number, since it is larger than the sum of its proper divisors (504913137).

1011211209 is an frugal number, since it uses more digits than its factorization.

1011211209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1387139 (or 1387124 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 18.

The square root of 1011211209 is about 31799.5473080986. The cubic root of 1011211209 is about 1003.7231903167.

It can be divided in two parts, 10112 and 11209, that added together give a triangular number (21321 = T₂₀₆).

The spelling of 1011211209 in words is "one billion, eleven million, two hundred eleven thousand, two hundred nine".