161840031 has 16 divisors (see below), whose sum is σ = 217945728. Its totient is φ = 106820000.

The previous prime is 161840023. The next prime is 161840033. The reversal of 161840031 is 130048161.

It is a cyclic number.

It is not a de Polignac number, because 161840031 - 2³ = 161840023 is a prime.

It is a super-2 number, since 2×161840031² = 52384391268161922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 161839983 and 161840010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161840033) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 147796 + ... + 148886.

It is an arithmetic number, because the mean of its divisors is an integer number (13621608).

Almost surely, 2^161840031 is an apocalyptic number.

161840031 is a deficient number, since it is larger than the sum of its proper divisors (56105697).

161840031 is a wasteful number, since it uses less digits than its factorization.

161840031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1542.

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 161840031 is about 12721.6363334282. The cubic root of 161840031 is about 544.9566848273.

Adding to 161840031 its reverse (130048161), we get a palindrome (291888192).

The spelling of 161840031 in words is "one hundred sixty-one million, eight hundred forty thousand, thirty-one".