161697211 has 4 divisors (see below), whose sum is σ = 174135472. Its totient is φ = 149258952.

The previous prime is 161697203. The next prime is 161697227. The reversal of 161697211 is 112796161.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 161697211 - 2³ = 161697203 is a prime.

It is a super-2 number, since 2×161697211² = 52291976090357042, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161697241) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6219111 + ... + 6219136.

It is an arithmetic number, because the mean of its divisors is an integer number (43533868).

Almost surely, 2^161697211 is an apocalyptic number.

161697211 is a deficient number, since it is larger than the sum of its proper divisors (12438261).

161697211 is a wasteful number, since it uses less digits than its factorization.

161697211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12438260.

The product of its digits is 4536, while the sum is 34.

The square root of 161697211 is about 12716.0218228816. The cubic root of 161697211 is about 544.7963338538.

The spelling of 161697211 in words is "one hundred sixty-one million, six hundred ninety-seven thousand, two hundred eleven".