161225816 has 8 divisors (see below), whose sum is σ = 302298420. Its totient is φ = 80612904.

The previous prime is 161225809. The next prime is 161225833. The reversal of 161225816 is 618522161.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10076606 + ... + 10076621.

Almost surely, 2^161225816 is an apocalyptic number.

It is an amenable number.

161225816 is a deficient number, since it is larger than the sum of its proper divisors (141072604).

161225816 is a wasteful number, since it uses less digits than its factorization.

161225816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20153233 (or 20153229 counting only the distinct ones).

The product of its digits is 5760, while the sum is 32.

The square root of 161225816 is about 12697.4728194236. The cubic root of 161225816 is about 544.2664046232.

Adding to 161225816 its reverse (618522161), we get a palindrome (779747977).

The spelling of 161225816 in words is "one hundred sixty-one million, two hundred twenty-five thousand, eight hundred sixteen".