2161798731 has 6 divisors (see below), whose sum is σ = 3122598180. Its totient is φ = 1441199148.

The previous prime is 2161798729. The next prime is 2161798817. The reversal of 2161798731 is 1378971612.

2161798731 is a `hidden beast` number, since 21 + 617 + 9 + 8 + 7 + 3 + 1 = 666.

It is not a de Polignac number, because 2161798731 - 2¹ = 2161798729 is a prime.

It is a super-2 number, since 2×2161798731² = 9346747506706420722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2161798231) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 120099921 + ... + 120099938.

It is an arithmetic number, because the mean of its divisors is an integer number (520433030).

Almost surely, 2^2161798731 is an apocalyptic number.

2161798731 is a deficient number, since it is larger than the sum of its proper divisors (960799449).

2161798731 is a wasteful number, since it uses less digits than its factorization.

2161798731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240199865 (or 240199862 counting only the distinct ones).

The product of its digits is 127008, while the sum is 45.

The square root of 2161798731 is about 46495.1473919591. The cubic root of 2161798731 is about 1293.0195337657.

The spelling of 2161798731 in words is "two billion, one hundred sixty-one million, seven hundred ninety-eight thousand, seven hundred thirty-one".