11891684401 has 3 divisors (see below), whose sum is σ = 11891793451. Its totient is φ = 11891575352.

The previous prime is 11891684393. The next prime is 11891684417. The reversal of 11891684401 is 10448619811.

The square root of 11891684401 is 109049.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 1962801 + 11889721600 = 1401^2 + 109040^2 .

It is not a de Polignac number, because 11891684401 - 2³ = 11891684393 is a prime.

It is a super-3 number, since 3×11891684401³ (a number of 31 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11891684491) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 54525 + ... + 163573.

Almost surely, 2^11891684401 is an apocalyptic number.

11891684401 is the 109049-th square number.

11891684401 is the 54525-th centered octagonal number.

It is an amenable number.

11891684401 is a deficient number, since it is larger than the sum of its proper divisors (109050).

11891684401 is an frugal number, since it uses more digits than its factorization.

11891684401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218098 (or 109049 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 43.

The spelling of 11891684401 in words is "eleven billion, eight hundred ninety-one million, six hundred eighty-four thousand, four hundred one".