161618400 has 108 divisors (see below), whose sum is σ = 569932272. Its totient is φ = 43096320.

The previous prime is 161618377. The next prime is 161618419. The reversal of 161618400 is 4816161.

161618400 is a `hidden beast` number, since 1 + 6 + 1 + 618 + 40 + 0 = 666.

It is a super-2 number, since 2×161618400² = 52241014437120000, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 17 ways as a sum of consecutive naturals, for example, 4024 + ... + 18423.

Almost surely, 2^161618400 is an apocalyptic number.

161618400 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 161618400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (284966136).

161618400 is an abundant number, since it is smaller than the sum of its proper divisors (408313872).

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

161618400 is a wasteful number, since it uses less digits than its factorization.

161618400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22473 (or 22457 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 161618400 is about 12712.9225593488. The cubic root of 161618400 is about 544.7078084733.

The spelling of 161618400 in words is "one hundred sixty-one million, six hundred eighteen thousand, four hundred".