161140631 has 4 divisors (see below), whose sum is σ = 161168064. Its totient is φ = 161113200.

The previous prime is 161140621. The next prime is 161140643. The reversal of 161140631 is 136041161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 136041161 = 883 ⋅154067.

It is a cyclic number.

It is not a de Polignac number, because 161140631 - 2¹⁰ = 161139607 is a prime.

It is a super-2 number, since 2×161140631² = 51932605918156322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 161140597 and 161140606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161140601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 935 + ... + 17976.

It is an arithmetic number, because the mean of its divisors is an integer number (40292016).

Almost surely, 2^161140631 is an apocalyptic number.

161140631 is a deficient number, since it is larger than the sum of its proper divisors (27433).

161140631 is an equidigital number, since it uses as much as digits as its factorization.

161140631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27432.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 161140631 is about 12694.1179685711. The cubic root of 161140631 is about 544.1705318432.

Adding to 161140631 its reverse (136041161), we get a palindrome (297181792).

The spelling of 161140631 in words is "one hundred sixty-one million, one hundred forty thousand, six hundred thirty-one".