161625729 has 8 divisors (see below), whose sum is σ = 222932160. Its totient is φ = 104034896.

The previous prime is 161625713. The next prime is 161625733. The reversal of 161625729 is 927526161.

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 161625729 - 2⁴ = 161625713 is a prime.

It is a super-2 number, since 2×161625729² = 52245752549562882, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161625029) by changing a digit.

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, 928797 + ... + 928970.

It is an arithmetic number, because the mean of its divisors is an integer number (27866520).

Almost surely, 2^161625729 is an apocalyptic number.

It is an amenable number.

161625729 is a deficient number, since it is larger than the sum of its proper divisors (61306431).

161625729 is a wasteful number, since it uses less digits than its factorization.

161625729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1857799.

The product of its digits is 45360, while the sum is 39.

The square root of 161625729 is about 12713.2108060867. The cubic root of 161625729 is about 544.7160420721.

The spelling of 161625729 in words is "one hundred sixty-one million, six hundred twenty-five thousand, seven hundred twenty-nine".