161276355225 has 36 divisors (see below), whose sum is σ = 305855871516. Its totient is φ = 80954403840.

The previous prime is 161276355223. The next prime is 161276355269. The reversal of 161276355225 is 522553672161.

It is a happy number.

161276355225 is a `hidden beast` number, since 1 + 6 + 1 + 2 + 7 + 635 + 5 + 2 + 2 + 5 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 21971243529 + 139305111696 = 148227^2 + 373236^2 .

It is not a de Polignac number, because 161276355225 - 2¹ = 161276355223 is a prime.

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

It is not an unprimeable number, because it can be changed into a prime (161276355221) 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, 21078052 + ... + 21085701.

It is an arithmetic number, because the mean of its divisors is an integer number (8495996431).

Almost surely, 2^161276355225 is an apocalyptic number.

161276355225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161276355225 is a deficient number, since it is larger than the sum of its proper divisors (144579516291).

161276355225 is a wasteful number, since it uses less digits than its factorization.

161276355225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42163786 (or 42163778 counting only the distinct ones).

The product of its digits is 756000, while the sum is 45.

The spelling of 161276355225 in words is "one hundred sixty-one billion, two hundred seventy-six million, three hundred fifty-five thousand, two hundred twenty-five".