161405400 has 96 divisors (see below), whose sum is σ = 538871760. Its totient is φ = 39728640.

The previous prime is 161405357. The next prime is 161405401. The reversal of 161405400 is 4504161.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161405401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2547 + ... + 18146.

Almost surely, 2^161405400 is an apocalyptic number.

161405400 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 161405400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (269435880).

161405400 is an abundant number, since it is smaller than the sum of its proper divisors (377466360).

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

161405400 is a wasteful number, since it uses less digits than its factorization.

161405400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20725 (or 20716 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 161405400 is about 12704.5424947142. The cubic root of 161405400 is about 544.4684096382.

Adding to 161405400 its reverse (4504161), we get a palindrome (165909561).

The spelling of 161405400 in words is "one hundred sixty-one million, four hundred five thousand, four hundred".