161665854 has 16 divisors (see below), whose sum is σ = 369522048. Its totient is φ = 46190232.

The previous prime is 161665843. The next prime is 161665897. The reversal of 161665854 is 458566161.

161665854 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×161665854³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (42), and also a Moran number because the ratio is a prime number: 3849187 = 161665854 / (1 + 6 + 1 + 6 + 6 + 5 + 8 + 5 + 4).

It is a Curzon number.

It is a congruent number.

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, 1924552 + ... + 1924635.

It is an arithmetic number, because the mean of its divisors is an integer number (23095128).

Almost surely, 2^161665854 is an apocalyptic number.

161665854 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

161665854 is an abundant number, since it is smaller than the sum of its proper divisors (207856194).

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

161665854 is a wasteful number, since it uses less digits than its factorization.

161665854 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3849199.

The product of its digits is 172800, while the sum is 42.

The square root of 161665854 is about 12714.7887910103. The cubic root of 161665854 is about 544.7611151820.

The spelling of 161665854 in words is "one hundred sixty-one million, six hundred sixty-five thousand, eight hundred fifty-four".