161225815 has 8 divisors (see below), whose sum is σ = 194281920. Its totient is φ = 128440032.

The previous prime is 161225809. The next prime is 161225833. The reversal of 161225815 is 518522161.

161225815 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 a cyclic number.

It is not a de Polignac number, because 161225815 - 2⁵ = 161225783 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 66264 + ... + 68653.

It is an arithmetic number, because the mean of its divisors is an integer number (24285240).

Almost surely, 2^161225815 is an apocalyptic number.

161225815 is a deficient number, since it is larger than the sum of its proper divisors (33056105).

161225815 is a wasteful number, since it uses less digits than its factorization.

161225815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135161.

The product of its digits is 4800, while the sum is 31.

The square root of 161225815 is about 12697.4727800456. The cubic root of 161225815 is about 544.2664034980.

Adding to 161225815 its reverse (518522161), we get a palindrome (679747976).

The spelling of 161225815 in words is "one hundred sixty-one million, two hundred twenty-five thousand, eight hundred fifteen".