11661201021066 has 16 divisors (see below), whose sum is σ = 23324874582144. Its totient is φ = 3886654917024.

The previous prime is 11661201021013. The next prime is 11661201021079. The reversal of 11661201021066 is 66012010216611.

11661201021066 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 102961186 + ... + 103074381.

It is an arithmetic number, because the mean of its divisors is an integer number (1457804661384).

Almost surely, 2^{11661201021066} is an apocalyptic number.

11661201021066 is an abundant number, since it is smaller than the sum of its proper divisors (11663673561078).

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

11661201021066 is a wasteful number, since it uses less digits than its factorization.

11661201021066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206045005.

The product of its (nonzero) digits is 5184, while the sum is 33.

Adding to 11661201021066 its reverse (66012010216611), we get a palindrome (77673211237677).

It can be divided in two parts, 1166120 and 1021066, that added together give a triangular number (2187186 = T₂₀₉₁).

The spelling of 11661201021066 in words is "eleven trillion, six hundred sixty-one billion, two hundred one million, twenty-one thousand, sixty-six".