161152721 has 8 divisors (see below), whose sum is σ = 162478080. Its totient is φ = 159831792.

The previous prime is 161152711. The next prime is 161152729. The reversal of 161152721 is 127251161.

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

It is a cyclic number.

It is not a de Polignac number, because 161152721 - 2¹⁸ = 160890577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161152729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 125360 + ... + 126638.

It is an arithmetic number, because the mean of its divisors is an integer number (20309760).

Almost surely, 2^161152721 is an apocalyptic number.

It is an amenable number.

161152721 is a deficient number, since it is larger than the sum of its proper divisors (1325359).

161152721 is a wasteful number, since it uses less digits than its factorization.

161152721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2215.

The product of its digits is 840, while the sum is 26.

The square root of 161152721 is about 12694.5941644465. The cubic root of 161152721 is about 544.1841407784.

The spelling of 161152721 in words is "one hundred sixty-one million, one hundred fifty-two thousand, seven hundred twenty-one".