161033111021 has 4 divisors (see below), whose sum is σ = 161453563392. Its totient is φ = 160612658652.

The previous prime is 161033111009. The next prime is 161033111059. The reversal of 161033111021 is 120111330161.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 161033111021 - 2⁶ = 161033110957 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 161033110984 and 161033111002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161033111321) 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, 210225611 + ... + 210226376.

It is an arithmetic number, because the mean of its divisors is an integer number (40363390848).

Almost surely, 2^161033111021 is an apocalyptic number.

It is an amenable number.

161033111021 is a deficient number, since it is larger than the sum of its proper divisors (420452371).

161033111021 is an equidigital number, since it uses as much as digits as its factorization.

161033111021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 420452370.

The product of its (nonzero) digits is 108, while the sum is 20.

Adding to 161033111021 its reverse (120111330161), we get a palindrome (281144441182).

The spelling of 161033111021 in words is "one hundred sixty-one billion, thirty-three million, one hundred eleven thousand, twenty-one".