161601321 has 16 divisors (see below), whose sum is σ = 248791424. Its totient is φ = 91390464.

The previous prime is 161601317. The next prime is 161601347. The reversal of 161601321 is 123106161.

161601321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 161601321 - 2² = 161601317 is a prime.

It is a super-2 number, since 2×161601321² = 52229973897890082, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (161601221) 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, 37630 + ... + 41703.

It is an arithmetic number, because the mean of its divisors is an integer number (15549464).

Almost surely, 2^161601321 is an apocalyptic number.

It is an amenable number.

161601321 is a deficient number, since it is larger than the sum of its proper divisors (87190103).

161601321 is an equidigital number, since it uses as much as digits as its factorization.

161601321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79440.

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 161601321 is about 12712.2508235167. The cubic root of 161601321 is about 544.6886204923.

Adding to 161601321 its reverse (123106161), we get a palindrome (284707482).

The spelling of 161601321 in words is "one hundred sixty-one million, six hundred one thousand, three hundred twenty-one".