161775901 has 12 divisors (see below), whose sum is σ = 188413500. Its totient is φ = 138499200.

The previous prime is 161775883. The next prime is 161775931. The reversal of 161775901 is 109577161.

It can be written as a sum of positive squares in 2 ways, for example, as 6175225 + 155600676 = 2485^2 + 12474^2 .

It is not a de Polignac number, because 161775901 - 2¹³ = 161767709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161775931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 57475 + ... + 60223.

It is an arithmetic number, because the mean of its divisors is an integer number (15701125).

Almost surely, 2^161775901 is an apocalyptic number.

It is an amenable number.

161775901 is a deficient number, since it is larger than the sum of its proper divisors (26637599).

161775901 is a wasteful number, since it uses less digits than its factorization.

161775901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3964 (or 3957 counting only the distinct ones).

The product of its (nonzero) digits is 13230, while the sum is 37.

The square root of 161775901 is about 12719.1155745987. The cubic root of 161775901 is about 544.8846946258.

The spelling of 161775901 in words is "one hundred sixty-one million, seven hundred seventy-five thousand, nine hundred one".