1211010985 has 16 divisors (see below), whose sum is σ = 1475398800. Its totient is φ = 954105856.

The previous prime is 1211010949. The next prime is 1211010989. The reversal of 1211010985 is 5890101121.

It can be written as a sum of positive squares in 8 ways, for example, as 15303744 + 1195707241 = 3912^2 + 34579^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211010985 - 2²⁷ = 1076793257 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1211010989) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 109071 + ... + 119659.

It is an arithmetic number, because the mean of its divisors is an integer number (92212425).

Almost surely, 2^1211010985 is an apocalyptic number.

It is an amenable number.

1211010985 is a deficient number, since it is larger than the sum of its proper divisors (264387815).

1211010985 is a wasteful number, since it uses less digits than its factorization.

1211010985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10940.

The product of its (nonzero) digits is 720, while the sum is 28.

The square root of 1211010985 is about 34799.5831153191. The cubic root of 1211010985 is about 1065.8989331791.

The spelling of 1211010985 in words is "one billion, two hundred eleven million, ten thousand, nine hundred eighty-five".