161440423 has 4 divisors (see below), whose sum is σ = 162949320. Its totient is φ = 159931528.

The previous prime is 161440421. The next prime is 161440429. The reversal of 161440423 is 324044161.

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 161440423 - 2¹ = 161440421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161440421) 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, 754288 + ... + 754501.

It is an arithmetic number, because the mean of its divisors is an integer number (40737330).

Almost surely, 2^161440423 is an apocalyptic number.

161440423 is a deficient number, since it is larger than the sum of its proper divisors (1508897).

161440423 is a wasteful number, since it uses less digits than its factorization.

161440423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1508896.

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 161440423 is about 12705.9207852088. The cubic root of 161440423 is about 544.5077877879.

Adding to 161440423 its reverse (324044161), we get a palindrome (485484584).

The spelling of 161440423 in words is "one hundred sixty-one million, four hundred forty thousand, four hundred twenty-three".