161641525 has 12 divisors (see below), whose sum is σ = 212226372. Its totient is φ = 121706240.

The previous prime is 161641499. The next prime is 161641537. The reversal of 161641525 is 525146161.

It can be written as a sum of positive squares in 6 ways, for example, as 17497489 + 144144036 = 4183^2 + 12006^2 .

It is not a de Polignac number, because 161641525 - 2⁹ = 161641013 is a prime.

It is a super-2 number, since 2×161641525² = 52255965208651250, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

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 11 ways as a sum of consecutive naturals, for example, 189742 + ... + 190591.

It is an arithmetic number, because the mean of its divisors is an integer number (17685531).

Almost surely, 2^161641525 is an apocalyptic number.

It is an amenable number.

161641525 is a deficient number, since it is larger than the sum of its proper divisors (50584847).

161641525 is a wasteful number, since it uses less digits than its factorization.

161641525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 380360 (or 380355 counting only the distinct ones).

The product of its digits is 7200, while the sum is 31.

The square root of 161641525 is about 12713.8320344419. The cubic root of 161641525 is about 544.7337868837.

Adding to 161641525 its reverse (525146161), we get a palindrome (686787686).

It can be divided in two parts, 16164 and 1525, that added together give a square (17689 = 133²).

The spelling of 161641525 in words is "one hundred sixty-one million, six hundred forty-one thousand, five hundred twenty-five".