161021985 has 8 divisors (see below), whose sum is σ = 257635200. Its totient is φ = 85878384.

The previous prime is 161021957. The next prime is 161022019. The reversal of 161021985 is 589120161.

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

It is not a de Polignac number, because 161021985 - 2¹⁶ = 160956449 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5367385 + ... + 5367414.

It is an arithmetic number, because the mean of its divisors is an integer number (32204400).

Almost surely, 2^161021985 is an apocalyptic number.

161021985 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161021985 is a deficient number, since it is larger than the sum of its proper divisors (96613215).

161021985 is a wasteful number, since it uses less digits than its factorization.

161021985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10734807.

The product of its (nonzero) digits is 4320, while the sum is 33.

The square root of 161021985 is about 12689.4438412406. The cubic root of 161021985 is about 544.0369435425.

The spelling of 161021985 in words is "one hundred sixty-one million, twenty-one thousand, nine hundred eighty-five".