161508813 has 8 divisors (see below), whose sum is σ = 215412000. Its totient is φ = 107639088.

The previous prime is 161508803. The next prime is 161508833. The reversal of 161508813 is 318805161.

161508813 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 161508813 - 2⁶ = 161508749 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161508803) 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, 6858 + ... + 19236.

It is an arithmetic number, because the mean of its divisors is an integer number (26926500).

Almost surely, 2^161508813 is an apocalyptic number.

It is an amenable number.

161508813 is a deficient number, since it is larger than the sum of its proper divisors (53903187).

161508813 is a wasteful number, since it uses less digits than its factorization.

161508813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16731.

The product of its (nonzero) digits is 5760, while the sum is 33.

The square root of 161508813 is about 12708.6117652559. The cubic root of 161508813 is about 544.5846657464.

The spelling of 161508813 in words is "one hundred sixty-one million, five hundred eight thousand, eight hundred thirteen".