161000161921 has 8 divisors (see below), whose sum is σ = 163016207424. Its totient is φ = 158985932880.

The previous prime is 161000161919. The next prime is 161000161961. The reversal of 161000161921 is 129161000161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 161000161921 - 2¹ = 161000161919 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 161000161921.

It is not an unprimeable number, because it can be changed into a prime (161000161901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 275301 + ... + 630706.

It is an arithmetic number, because the mean of its divisors is an integer number (20377025928).

Almost surely, 2^161000161921 is an apocalyptic number.

It is an amenable number.

161000161921 is a deficient number, since it is larger than the sum of its proper divisors (2016045503).

161000161921 is an equidigital number, since it uses as much as digits as its factorization.

161000161921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 908231.

The product of its (nonzero) digits is 648, while the sum is 28.

The spelling of 161000161921 in words is "one hundred sixty-one billion, one hundred sixty-one thousand, nine hundred twenty-one".