1211500011 has 16 divisors (see below), whose sum is σ = 1637023520. Its totient is φ = 796884480.

The previous prime is 1211499979. The next prime is 1211500039. The reversal of 1211500011 is 1100051121.

It is not a de Polignac number, because 1211500011 - 2⁵ = 1211499979 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1211500011.

It is not an unprimeable number, because it can be changed into a prime (1211500061) 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, 71121 + ... + 86493.

It is an arithmetic number, because the mean of its divisors is an integer number (102313970).

Almost surely, 2^1211500011 is an apocalyptic number.

1211500011 is a deficient number, since it is larger than the sum of its proper divisors (425523509).

1211500011 is a wasteful number, since it uses less digits than its factorization.

1211500011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15726.

The product of its (nonzero) digits is 10, while the sum is 12.

The square root of 1211500011 is about 34806.6087259302. The cubic root of 1211500011 is about 1066.0423896659.

Adding to 1211500011 its reverse (1100051121), we get a palindrome (2311551132).

The spelling of 1211500011 in words is "one billion, two hundred eleven million, five hundred thousand, eleven".