161515856 has 20 divisors (see below), whose sum is σ = 313834452. Its totient is φ = 80526336.

The previous prime is 161515853. The next prime is 161515883. The reversal of 161515856 is 658515161.

It can be written as a sum of positive squares in 2 ways, for example, as 127690000 + 33825856 = 11300^2 + 5816^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161515853) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8651 + ... + 19946.

Almost surely, 2^161515856 is an apocalyptic number.

161515856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

161515856 is a deficient number, since it is larger than the sum of its proper divisors (152318596).

161515856 is a wasteful number, since it uses less digits than its factorization.

161515856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28958 (or 28952 counting only the distinct ones).

The product of its digits is 36000, while the sum is 38.

The square root of 161515856 is about 12708.8888578034. Note that the first 4 decimals coincide. The cubic root of 161515856 is about 544.5925816283.

It can be divided in two parts, 1615 and 15856, that added together give a palindrome (17471).

The spelling of 161515856 in words is "one hundred sixty-one million, five hundred fifteen thousand, eight hundred fifty-six".