161869291 has 4 divisors (see below), whose sum is σ = 171391032. Its totient is φ = 152347552.

The previous prime is 161869289. The next prime is 161869307. The reversal of 161869291 is 192968161.

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 161869291 - 2¹ = 161869289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161869231) 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, 4760845 + ... + 4760878.

It is an arithmetic number, because the mean of its divisors is an integer number (42847758).

Almost surely, 2^161869291 is an apocalyptic number.

161869291 is a deficient number, since it is larger than the sum of its proper divisors (9521741).

161869291 is an equidigital number, since it uses as much as digits as its factorization.

161869291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9521740.

The product of its digits is 46656, while the sum is 43.

The square root of 161869291 is about 12722.7862907462. The cubic root of 161869291 is about 544.9895248106.

The spelling of 161869291 in words is "one hundred sixty-one million, eight hundred sixty-nine thousand, two hundred ninety-one".