161784428 has 24 divisors (see below), whose sum is σ = 307761552. Its totient is φ = 73969344.

The previous prime is 161784419. The next prime is 161784439. The reversal of 161784428 is 824487161.

It is a super-2 number, since 2×161784428² = 52348402286574368, which contains 22 as substring.

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8975 + ... + 20102.

It is an arithmetic number, because the mean of its divisors is an integer number (12823398).

Almost surely, 2^161784428 is an apocalyptic number.

It is an amenable number.

161784428 is a deficient number, since it is larger than the sum of its proper divisors (145977124).

161784428 is a wasteful number, since it uses less digits than its factorization.

161784428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29201 (or 29199 counting only the distinct ones).

The product of its digits is 86016, while the sum is 41.

The square root of 161784428 is about 12719.4507743063. The cubic root of 161784428 is about 544.8942678484.

The spelling of 161784428 in words is "one hundred sixty-one million, seven hundred eighty-four thousand, four hundred twenty-eight".