11921212864 has 56 divisors (see below), whose sum is σ = 27164995200. Its totient is φ = 5133530880.

The previous prime is 11921212861. The next prime is 11921212871. The reversal of 11921212864 is 46821212911.

It is a super-2 number, since 2×11921212864² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11921212861) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 432244 + ... + 458995.

It is an arithmetic number, because the mean of its divisors is an integer number (485089200).

Almost surely, 2^11921212864 is an apocalyptic number.

It is an amenable number.

11921212864 is an abundant number, since it is smaller than the sum of its proper divisors (15243782336).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

11921212864 is a wasteful number, since it uses less digits than its factorization.

11921212864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 891281 (or 891271 counting only the distinct ones).

The product of its digits is 13824, while the sum is 37.

It can be divided in two parts, 11921 and 212864, that added together give a triangular number (224785 = T₆₇₀).

The spelling of 11921212864 in words is "eleven billion, nine hundred twenty-one million, two hundred twelve thousand, eight hundred sixty-four".