165721142 has 8 divisors (see below), whose sum is σ = 253272096. Its totient is φ = 81297112.

The previous prime is 165721099. The next prime is 165721159. The reversal of 165721142 is 241127561.

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

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 781598 + ... + 781809.

It is an arithmetic number, because the mean of its divisors is an integer number (31659012).

Almost surely, 2^165721142 is an apocalyptic number.

165721142 is a deficient number, since it is larger than the sum of its proper divisors (87550954).

165721142 is a wasteful number, since it uses less digits than its factorization.

165721142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1563462.

The product of its digits is 3360, while the sum is 29.

The square root of 165721142 is about 12873.2723889460. The cubic root of 165721142 is about 549.2785493833.

The spelling of 165721142 in words is "one hundred sixty-five million, seven hundred twenty-one thousand, one hundred forty-two".