161661475 has 24 divisors (see below), whose sum is σ = 205701120. Its totient is φ = 125989920.

The previous prime is 161661427. The next prime is 161661499. The reversal of 161661475 is 574166161.

It is not a de Polignac number, because 161661475 - 2⁹ = 161660963 is a prime.

It is a super-2 number, since 2×161661475² = 52268864998351250, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 186894 + ... + 187756.

It is an arithmetic number, because the mean of its divisors is an integer number (8570880).

Almost surely, 2^161661475 is an apocalyptic number.

161661475 is a deficient number, since it is larger than the sum of its proper divisors (44039645).

161661475 is a wasteful number, since it uses less digits than its factorization.

161661475 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1059 (or 1054 counting only the distinct ones).

The product of its digits is 30240, while the sum is 37.

The square root of 161661475 is about 12714.6165887926. The cubic root of 161661475 is about 544.7561965378.

The spelling of 161661475 in words is "one hundred sixty-one million, six hundred sixty-one thousand, four hundred seventy-five".