161684040 has 128 divisors (see below), whose sum is σ = 562360320. Its totient is φ = 36422400.

The previous prime is 161684023. The next prime is 161684041. The reversal of 161684040 is 40486161.

It is a super-2 number, since 2×161684040² = 52283457581443200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 161683989 and 161684007.

It is not an unprimeable number, because it can be changed into a prime (161684041) 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 31 ways as a sum of consecutive naturals, for example, 58285 + ... + 60995.

It is an arithmetic number, because the mean of its divisors is an integer number (4393440).

Almost surely, 2^161684040 is an apocalyptic number.

161684040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161684040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (281180160).

161684040 is an abundant number, since it is smaller than the sum of its proper divisors (400676280).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161684040 is a wasteful number, since it uses less digits than its factorization.

161684040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2803 (or 2799 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 161684040 is about 12715.5039223776. The cubic root of 161684040 is about 544.7815413758.

The spelling of 161684040 in words is "one hundred sixty-one million, six hundred eighty-four thousand, forty".