161772783666 has 32 divisors (see below), whose sum is σ = 368929790208. Its totient is φ = 46848226560.

The previous prime is 161772783661. The next prime is 161772783677. The reversal of 161772783666 is 666387277161.

It is not an unprimeable number, because it can be changed into a prime (161772783661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60998970 + ... + 61001621.

It is an arithmetic number, because the mean of its divisors is an integer number (11529055944).

Almost surely, 2^161772783666 is an apocalyptic number.

161772783666 is an abundant number, since it is smaller than the sum of its proper divisors (207157006542).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161772783666 is a wasteful number, since it uses less digits than its factorization.

161772783666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122000626.

The product of its digits is 21337344, while the sum is 60.

The spelling of 161772783666 in words is "one hundred sixty-one billion, seven hundred seventy-two million, seven hundred eighty-three thousand, six hundred sixty-six".