161807994 has 24 divisors (see below), whose sum is σ = 362674260. Its totient is φ = 52075968.

The previous prime is 161807983. The next prime is 161807999. The reversal of 161807994 is 499708161.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 142491969 + 19316025 = 11937^2 + 4395^2 .

It is not an unprimeable number, because it can be changed into a prime (161807999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 154467 + ... + 155510.

Almost surely, 2^161807994 is an apocalyptic number.

161807994 is an abundant number, since it is smaller than the sum of its proper divisors (200866266).

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

161807994 is a wasteful number, since it uses less digits than its factorization.

161807994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310014 (or 310011 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 45.

The square root of 161807994 is about 12720.3771170512. The cubic root of 161807994 is about 544.9207235361.

The spelling of 161807994 in words is "one hundred sixty-one million, eight hundred seven thousand, nine hundred ninety-four".