161708780947 has 6 divisors (see below), whose sum is σ = 188110214628. Its totient is φ = 138607526484.

The previous prime is 161708780843. The next prime is 161708780951. The reversal of 161708780947 is 749087807161.

It is a de Polignac number, because none of the positive numbers 2^k-161708780947 is a prime.

It is a super-2 number, since 2×161708780947² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 161708780891 and 161708780900.

It is not an unprimeable number, because it can be changed into a prime (161708780747) 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, 1650089553 + ... + 1650089650.

It is an arithmetic number, because the mean of its divisors is an integer number (31351702438).

Almost surely, 2^161708780947 is an apocalyptic number.

161708780947 is a deficient number, since it is larger than the sum of its proper divisors (26401433681).

161708780947 is an equidigital number, since it uses as much as digits as its factorization.

161708780947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3300179217 (or 3300179210 counting only the distinct ones).

The product of its (nonzero) digits is 4741632, while the sum is 58.

The spelling of 161708780947 in words is "one hundred sixty-one billion, seven hundred eight million, seven hundred eighty thousand, nine hundred forty-seven".