15661660115011 has 4 divisors (see below), whose sum is σ = 15661672048800. Its totient is φ = 15661648181224.

The previous prime is 15661660115009. The next prime is 15661660115071. The reversal of 15661660115011 is 11051106616651.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 15661660115011 - 2¹ = 15661660115009 is a prime.

It is a super-3 number, since 3×15661660115011³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15661660115071) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3715051 + ... + 6717508.

It is an arithmetic number, because the mean of its divisors is an integer number (3915418012200).

Almost surely, 2^{15661660115011} is an apocalyptic number.

15661660115011 is a deficient number, since it is larger than the sum of its proper divisors (11933789).

15661660115011 is a wasteful number, since it uses less digits than its factorization.

15661660115011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11933788.

The product of its (nonzero) digits is 32400, while the sum is 40.

The spelling of 15661660115011 in words is "fifteen trillion, six hundred sixty-one billion, six hundred sixty million, one hundred fifteen thousand, eleven".