161866971 has 64 divisors (see below), whose sum is σ = 286003200. Its totient is φ = 88553088.

The previous prime is 161866949. The next prime is 161866993. The reversal of 161866971 is 179668161.

It is an interprime number because it is at equal distance from previous prime (161866949) and next prime (161866993).

It is not a de Polignac number, because 161866971 - 2¹³ = 161858779 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161867971) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 552301 + ... + 552593.

It is an arithmetic number, because the mean of its divisors is an integer number (4468800).

Almost surely, 2^161866971 is an apocalyptic number.

161866971 is a deficient number, since it is larger than the sum of its proper divisors (124136229).

161866971 is a wasteful number, since it uses less digits than its factorization.

161866971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 425 (or 419 counting only the distinct ones).

The product of its digits is 108864, while the sum is 45.

The square root of 161866971 is about 12722.6951154227. The cubic root of 161866971 is about 544.9869211013.

The spelling of 161866971 in words is "one hundred sixty-one million, eight hundred sixty-six thousand, nine hundred seventy-one".