161665047 has 12 divisors (see below), whose sum is σ = 236473120. Its totient is φ = 106411968.

The previous prime is 161665039. The next prime is 161665051. The reversal of 161665047 is 740566161.

It is not a de Polignac number, because 161665047 - 2³ = 161665039 is a prime.

It is a super-2 number, since 2×161665047² = 52271174843024418, 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 (161665057) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 112978 + ... + 114399.

Almost surely, 2^161665047 is an apocalyptic number.

161665047 is a deficient number, since it is larger than the sum of its proper divisors (74808073).

161665047 is a wasteful number, since it uses less digits than its factorization.

161665047 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 227462 (or 227459 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 161665047 is about 12714.7570562713. The cubic root of 161665047 is about 544.7602087384.

The spelling of 161665047 in words is "one hundred sixty-one million, six hundred sixty-five thousand, forty-seven".