161600400 has 240 divisors, whose sum is σ = 619960320. Its totient is φ = 39744000.

The previous prime is 161600347. The next prime is 161600437. The reversal of 161600400 is 4006161.

161600400 is a `hidden beast` number, since 1 + 61 + 600 + 4 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a super-2 number, since 2×161600400² = 52229378560320000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 139825 + ... + 140975.

It is an arithmetic number, because the mean of its divisors is an integer number (2583168).

Almost surely, 2^161600400 is an apocalyptic number.

161600400 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 161600400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (309980160).

161600400 is an abundant number, since it is smaller than the sum of its proper divisors (458359920).

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

161600400 is a wasteful number, since it uses less digits than its factorization.

161600400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1191 (or 1174 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 161600400 is about 12712.2145985662. The cubic root of 161600400 is about 544.6875857252.

Adding to 161600400 its reverse (4006161), we get a palindrome (165606561).

The spelling of 161600400 in words is "one hundred sixty-one million, six hundred thousand, four hundred".