161601625 has 8 divisors (see below), whose sum is σ = 201678984. Its totient is φ = 129281200.

The previous prime is 161601619. The next prime is 161601637. The reversal of 161601625 is 526106161.

It can be written as a sum of positive squares in 4 ways, for example, as 82944 + 161518681 = 288^2 + 12709^2 .

It is not a de Polignac number, because 161601625 - 2³ = 161601617 is a prime.

It is a super-2 number, since 2×161601625² = 52230170405281250, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 161601593 and 161601602.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 646282 + ... + 646531.

It is an arithmetic number, because the mean of its divisors is an integer number (25209873).

Almost surely, 2^161601625 is an apocalyptic number.

It is an amenable number.

161601625 is a deficient number, since it is larger than the sum of its proper divisors (40077359).

161601625 is an equidigital number, since it uses as much as digits as its factorization.

161601625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1292828 (or 1292818 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 161601625 is about 12712.2627804809. The cubic root of 161601625 is about 544.6889620432.

Adding to 161601625 its reverse (526106161), we get a palindrome (687707786).

The spelling of 161601625 in words is "one hundred sixty-one million, six hundred one thousand, six hundred twenty-five".