161778753 has 6 divisors (see below), whose sum is σ = 233680434. Its totient is φ = 107852496.

The previous prime is 161778751. The next prime is 161778761. The reversal of 161778753 is 357877161.

It can be written as a sum of positive squares in only one way, i.e., 134026929 + 27751824 = 11577^2 + 5268^2 .

It is not a de Polignac number, because 161778753 - 2¹ = 161778751 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 161778699 and 161778708.

It is not an unprimeable number, because it can be changed into a prime (161778751) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8987700 + ... + 8987717.

It is an arithmetic number, because the mean of its divisors is an integer number (38946739).

Almost surely, 2^161778753 is an apocalyptic number.

It is an amenable number.

161778753 is a deficient number, since it is larger than the sum of its proper divisors (71901681).

161778753 is a wasteful number, since it uses less digits than its factorization.

161778753 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17975423 (or 17975420 counting only the distinct ones).

The product of its digits is 246960, while the sum is 45.

The square root of 161778753 is about 12719.2276888182. The cubic root of 161778753 is about 544.8878965902.

The spelling of 161778753 in words is "one hundred sixty-one million, seven hundred seventy-eight thousand, seven hundred fifty-three".