161399090 has 16 divisors (see below), whose sum is σ = 291738240. Its totient is φ = 64288560.

The previous prime is 161399087. The next prime is 161399099. The reversal of 161399090 is 90993161.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (161399099) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31376 + ... + 36155.

It is an arithmetic number, because the mean of its divisors is an integer number (18233640).

Almost surely, 2^161399090 is an apocalyptic number.

161399090 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

161399090 is a deficient number, since it is larger than the sum of its proper divisors (130339150).

161399090 is a wasteful number, since it uses less digits than its factorization.

161399090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67777.

The product of its (nonzero) digits is 13122, while the sum is 38.

The square root of 161399090 is about 12704.2941559144. The cubic root of 161399090 is about 544.4613143769.

The spelling of 161399090 in words is "one hundred sixty-one million, three hundred ninety-nine thousand, ninety".