161405100 has 162 divisors, whose sum is σ = 523927404. Its totient is φ = 41558400.

The previous prime is 161405093. The next prime is 161405143. The reversal of 161405100 is 1504161.

161405100 is a `hidden beast` number, since 1 + 614 + 0 + 51 + 0 + 0 = 666.

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 53 ways as a sum of consecutive naturals, for example, 1232035 + ... + 1232165.

Almost surely, 2^161405100 is an apocalyptic number.

161405100 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 161405100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (261963702).

161405100 is an abundant number, since it is smaller than the sum of its proper divisors (362522304).

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

161405100 is a wasteful number, since it uses less digits than its factorization.

161405100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 225 (or 178 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 161405100 is about 12704.5306879082. The cubic root of 161405100 is about 544.4680723082.

Adding to 161405100 its reverse (1504161), we get a palindrome (162909261).

The spelling of 161405100 in words is "one hundred sixty-one million, four hundred five thousand, one hundred".