11909571556 has 6 divisors (see below), whose sum is σ = 20841750230. Its totient is φ = 5954785776.

The previous prime is 11909571551. The next prime is 11909571563. The reversal of 11909571556 is 65517590911.

It can be written as a sum of positive squares in only one way, i.e., 10768212900 + 1141358656 = 103770^2 + 33784^2 .

It is a super-2 number, since 2×11909571556² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (11909571551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1488696441 + ... + 1488696448.

Almost surely, 2^11909571556 is an apocalyptic number.

It is an amenable number.

11909571556 is a deficient number, since it is larger than the sum of its proper divisors (8932178674).

11909571556 is a wasteful number, since it uses less digits than its factorization.

11909571556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2977392893 (or 2977392891 counting only the distinct ones).

The product of its (nonzero) digits is 425250, while the sum is 49.

The spelling of 11909571556 in words is "eleven billion, nine hundred nine million, five hundred seventy-one thousand, five hundred fifty-six".