11956766409 has 81 divisors (see below), whose sum is σ = 20756010951. Its totient is φ = 6613306560.

The previous prime is 11956766399. The next prime is 11956766411. The reversal of 11956766409 is 90466765911.

It is a happy number.

The square root of 11956766409 is 109347.

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

11956766409 is a `hidden beast` number, since 1 + 19 + 567 + 6 + 64 + 0 + 9 = 666.

11956766409 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 576144009 + 11380622400 = 24003^2 + 106680^2 .

It is not a de Polignac number, because 11956766409 - 2²¹ = 11954669257 is a prime.

It is not an unprimeable number, because it can be changed into a prime (11956766429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 94147704 + ... + 94147830.

Almost surely, 2^11956766409 is an apocalyptic number.

11956766409 is the 109347-th square number.

11956766409 is the 54674-th centered octagonal number.

It is an amenable number.

11956766409 is a deficient number, since it is larger than the sum of its proper divisors (8799244542).

11956766409 is an equidigital number, since it uses as much as digits as its factorization.

11956766409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 356 (or 178 counting only the distinct ones).

The product of its (nonzero) digits is 2449440, while the sum is 54.

The spelling of 11956766409 in words is "eleven billion, nine hundred fifty-six million, seven hundred sixty-six thousand, four hundred nine".