161818724 has 12 divisors (see below), whose sum is σ = 292947900. Its totient is φ = 78119328.

The previous prime is 161818717. The next prime is 161818751. The reversal of 161818724 is 427818161.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 71910400 + 89908324 = 8480^2 + 9482^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 697379 + ... + 697610.

It is an arithmetic number, because the mean of its divisors is an integer number (24412325).

Almost surely, 2^161818724 is an apocalyptic number.

It is an amenable number.

161818724 is a deficient number, since it is larger than the sum of its proper divisors (131129176).

161818724 is a wasteful number, since it uses less digits than its factorization.

161818724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1395022 (or 1395020 counting only the distinct ones).

The product of its digits is 21504, while the sum is 38.

The square root of 161818724 is about 12720.7988742846. The cubic root of 161818724 is about 544.9327684089.

The spelling of 161818724 in words is "one hundred sixty-one million, eight hundred eighteen thousand, seven hundred twenty-four".