11651561211 has 4 divisors (see below), whose sum is σ = 15535414952. Its totient is φ = 7767707472.

The previous prime is 11651561189. The next prime is 11651561227. The reversal of 11651561211 is 11216515611.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 11651561211 - 2⁶ = 11651561147 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11651561231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1941926866 + ... + 1941926871.

It is an arithmetic number, because the mean of its divisors is an integer number (3883853738).

Almost surely, 2^11651561211 is an apocalyptic number.

11651561211 is a deficient number, since it is larger than the sum of its proper divisors (3883853741).

11651561211 is an equidigital number, since it uses as much as digits as its factorization.

11651561211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3883853740.

The product of its digits is 1800, while the sum is 30.

The spelling of 11651561211 in words is "eleven billion, six hundred fifty-one million, five hundred sixty-one thousand, two hundred eleven".