161511656111 has 16 divisors (see below), whose sum is σ = 177309573504. Its totient is φ = 146215342944.

The previous prime is 161511656107. The next prime is 161511656129. The reversal of 161511656111 is 111656115161.

It is a cyclic number.

It is not a de Polignac number, because 161511656111 - 2² = 161511656107 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161511656171) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 210725 + ... + 606158.

It is an arithmetic number, because the mean of its divisors is an integer number (11081848344).

Almost surely, 2^161511656111 is an apocalyptic number.

161511656111 is a deficient number, since it is larger than the sum of its proper divisors (15797917393).

161511656111 is a wasteful number, since it uses less digits than its factorization.

161511656111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 817190.

The product of its digits is 5400, while the sum is 35.

The spelling of 161511656111 in words is "one hundred sixty-one billion, five hundred eleven million, six hundred fifty-six thousand, one hundred eleven".