161650011121 has 4 divisors (see below), whose sum is σ = 161674625700. Its totient is φ = 161625396544.

The previous prime is 161650011079. The next prime is 161650011143. The reversal of 161650011121 is 121110056161.

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

It can be written as a sum of positive squares in 2 ways, for example, as 132601581025 + 29048430096 = 364145^2 + 170436^2 .

It is a cyclic number.

It is not a de Polignac number, because 161650011121 - 2²⁵ = 161616456689 is a prime.

It is a super-2 number, since 2×161650011121² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161650017121) 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, 12297436 + ... + 12310573.

It is an arithmetic number, because the mean of its divisors is an integer number (40418656425).

Almost surely, 2^161650011121 is an apocalyptic number.

It is an amenable number.

161650011121 is a deficient number, since it is larger than the sum of its proper divisors (24614579).

161650011121 is an equidigital number, since it uses as much as digits as its factorization.

161650011121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24614578.

The product of its (nonzero) digits is 360, while the sum is 25.

Adding to 161650011121 its reverse (121110056161), we get a palindrome (282760067282).

The spelling of 161650011121 in words is "one hundred sixty-one billion, six hundred fifty million, eleven thousand, one hundred twenty-one".