161803650825 has 36 divisors (see below), whose sum is σ = 289917176380. Its totient is φ = 86262865920.

The previous prime is 161803650769. The next prime is 161803650829. The reversal of 161803650825 is 528056308161.

161803650825 is a `hidden beast` number, since 1 + 61 + 80 + 3 + 6 + 508 + 2 + 5 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 780420096 + 161023230729 = 27936^2 + 401277^2 .

It is not a de Polignac number, because 161803650825 - 2⁹ = 161803650313 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (161803650829) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 471309 + ... + 738741.

Almost surely, 2^161803650825 is an apocalyptic number.

161803650825 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161803650825 is a deficient number, since it is larger than the sum of its proper divisors (128113525555).

161803650825 is a wasteful number, since it uses less digits than its factorization.

161803650825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270138 (or 270130 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 45.

Adding to 161803650825 its reverse (528056308161), we get a palindrome (689859958986).

The spelling of 161803650825 in words is "one hundred sixty-one billion, eight hundred three million, six hundred fifty thousand, eight hundred twenty-five".