161806803225 has 24 divisors (see below), whose sum is σ = 267576921600. Its totient is φ = 86278787520.

The previous prime is 161806803163. The next prime is 161806803229. The reversal of 161806803225 is 522308608161.

It is not a de Polignac number, because 161806803225 - 2⁹ = 161806802713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161806803229) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 135147 + ... + 584703.

It is an arithmetic number, because the mean of its divisors is an integer number (11149038400).

Almost surely, 2^161806803225 is an apocalyptic number.

161806803225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161806803225 is a deficient number, since it is larger than the sum of its proper divisors (105770118375).

161806803225 is a wasteful number, since it uses less digits than its factorization.

161806803225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 454369 (or 454364 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 42.

The spelling of 161806803225 in words is "one hundred sixty-one billion, eight hundred six million, eight hundred three thousand, two hundred twenty-five".