11211996861 has 16 divisors (see below), whose sum is σ = 17888086720. Its totient is φ = 6899690160.

The previous prime is 11211996857. The next prime is 11211996863. The reversal of 11211996861 is 16869911211.

It is not a de Polignac number, because 11211996861 - 2² = 11211996857 is a prime.

It is a super-2 number, since 2×11211996861² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11211996863) 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, 15971155 + ... + 15971856.

It is an arithmetic number, because the mean of its divisors is an integer number (1118005420).

Almost surely, 2^11211996861 is an apocalyptic number.

It is an amenable number.

11211996861 is a deficient number, since it is larger than the sum of its proper divisors (6676089859).

11211996861 is a wasteful number, since it uses less digits than its factorization.

11211996861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31943033 (or 31943027 counting only the distinct ones).

The product of its digits is 46656, while the sum is 45.

The spelling of 11211996861 in words is "eleven billion, two hundred eleven million, nine hundred ninety-six thousand, eight hundred sixty-one".