1261011115166 has 64 divisors (see below), whose sum is σ = 2117490584832. Its totient is φ = 558420000000.

The previous prime is 1261011115139. The next prime is 1261011115171. The reversal of 1261011115166 is 6615111101621.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 46277306 + ... + 46304546.

It is an arithmetic number, because the mean of its divisors is an integer number (33085790388).

Almost surely, 2^{1261011115166} is an apocalyptic number.

1261011115166 is a deficient number, since it is larger than the sum of its proper divisors (856479469666).

1261011115166 is a wasteful number, since it uses less digits than its factorization.

1261011115166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27689.

The product of its (nonzero) digits is 2160, while the sum is 32.

Adding to 1261011115166 its reverse (6615111101621), we get a palindrome (7876122216787).

The spelling of 1261011115166 in words is "one trillion, two hundred sixty-one billion, eleven million, one hundred fifteen thousand, one hundred sixty-six".