161858728 has 16 divisors (see below), whose sum is σ = 316680480. Its totient is φ = 77410608.

The previous prime is 161858699. The next prime is 161858731. The reversal of 161858728 is 827858161.

161858728 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 439650 + ... + 440017.

It is an arithmetic number, because the mean of its divisors is an integer number (19792530).

Almost surely, 2^161858728 is an apocalyptic number.

It is an amenable number.

161858728 is a deficient number, since it is larger than the sum of its proper divisors (154821752).

161858728 is a wasteful number, since it uses less digits than its factorization.

161858728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 879696 (or 879692 counting only the distinct ones).

The product of its digits is 215040, while the sum is 46.

The square root of 161858728 is about 12722.3711626410. The cubic root of 161858728 is about 544.9776698760.

The spelling of 161858728 in words is "one hundred sixty-one million, eight hundred fifty-eight thousand, seven hundred twenty-eight".