11666516001555 has 16 divisors (see below), whose sum is σ = 18837677216160. Its totient is φ = 6165057996288.

The previous prime is 11666516001551. The next prime is 11666516001643. The reversal of 11666516001555 is 55510061566611.

It is not a de Polignac number, because 11666516001555 - 2² = 11666516001551 is a prime.

It is a super-2 number, since 2×11666516001555² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (11666516001551) 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 in 15 ways as a sum of consecutive naturals, for example, 3567740262 + ... + 3567743531.

It is an arithmetic number, because the mean of its divisors is an integer number (1177354826010).

Almost surely, 2^{11666516001555} is an apocalyptic number.

11666516001555 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

11666516001555 is a deficient number, since it is larger than the sum of its proper divisors (7171161214605).

11666516001555 is a wasteful number, since it uses less digits than its factorization.

11666516001555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7135483910.

The product of its (nonzero) digits is 810000, while the sum is 48.

The spelling of 11666516001555 in words is "eleven trillion, six hundred sixty-six billion, five hundred sixteen million, one thousand, five hundred fifty-five".