161806731 has 8 divisors (see below), whose sum is σ = 228433104. Its totient is φ = 101525760.

The previous prime is 161806693. The next prime is 161806739. The reversal of 161806731 is 137608161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 161806731 - 2¹⁴ = 161790347 is a prime.

It is a super-2 number, since 2×161806731² = 52362836393812722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 161806692 and 161806701.

It is not an unprimeable number, because it can be changed into a prime (161806739) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1586290 + ... + 1586391.

It is an arithmetic number, because the mean of its divisors is an integer number (28554138).

Almost surely, 2^161806731 is an apocalyptic number.

161806731 is a deficient number, since it is larger than the sum of its proper divisors (66626373).

161806731 is a wasteful number, since it uses less digits than its factorization.

161806731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3172701.

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 161806731 is about 12720.3274721998. The cubic root of 161806731 is about 544.9193057308.

The spelling of 161806731 in words is "one hundred sixty-one million, eight hundred six thousand, seven hundred thirty-one".