161661607 has 8 divisors (see below), whose sum is σ = 165731184. Its totient is φ = 157629888.

The previous prime is 161661589. The next prime is 161661613. The reversal of 161661607 is 706166161.

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 161661607 - 2²⁷ = 27443879 is a prime.

It is a super-2 number, since 2×161661607² = 52268950355644898, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161661637) by changing a digit.

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, 718 + ... + 17995.

It is an arithmetic number, because the mean of its divisors is an integer number (20716398).

Almost surely, 2^161661607 is an apocalyptic number.

161661607 is a deficient number, since it is larger than the sum of its proper divisors (4069577).

161661607 is a wasteful number, since it uses less digits than its factorization.

161661607 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18929.

The product of its (nonzero) digits is 9072, while the sum is 34.

The square root of 161661607 is about 12714.6217796677. The cubic root of 161661607 is about 544.7563448060.

The spelling of 161661607 in words is "one hundred sixty-one million, six hundred sixty-one thousand, six hundred seven".