161554665 has 8 divisors (see below), whose sum is σ = 258487488. Its totient is φ = 86162480.

The previous prime is 161554649. The next prime is 161554693. The reversal of 161554665 is 566455161.

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

It is not a de Polignac number, because 161554665 - 2⁴ = 161554649 is a prime.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 5385141 + ... + 5385170.

It is an arithmetic number, because the mean of its divisors is an integer number (32310936).

Almost surely, 2^161554665 is an apocalyptic number.

161554665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161554665 is a deficient number, since it is larger than the sum of its proper divisors (96932823).

161554665 is a wasteful number, since it uses less digits than its factorization.

161554665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10770319.

The product of its digits is 108000, while the sum is 39.

The square root of 161554665 is about 12710.4156108288. The cubic root of 161554665 is about 544.6361963368.

It can be divided in two parts, 1615 and 54665, that added together give a triangular number (56280 = T₃₃₅).

The spelling of 161554665 in words is "one hundred sixty-one million, five hundred fifty-four thousand, six hundred sixty-five".