161987785 has 8 divisors (see below), whose sum is σ = 195073920. Its totient is φ = 129131184.

The previous prime is 161987783. The next prime is 161987801. The reversal of 161987785 is 587789161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 161987785 - 2¹ = 161987783 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161987783) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55825 + ... + 58654.

It is an arithmetic number, because the mean of its divisors is an integer number (24384240).

Almost surely, 2^161987785 is an apocalyptic number.

It is an amenable number.

161987785 is a deficient number, since it is larger than the sum of its proper divisors (33086135).

161987785 is a wasteful number, since it uses less digits than its factorization.

161987785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114767.

The product of its digits is 846720, while the sum is 52.

The square root of 161987785 is about 12727.4422017937. The cubic root of 161987785 is about 545.1224761917.

The spelling of 161987785 in words is "one hundred sixty-one million, nine hundred eighty-seven thousand, seven hundred eighty-five".