161040400 has 30 divisors (see below), whose sum is σ = 386900522. Its totient is φ = 64416000.

The previous prime is 161040361. The next prime is 161040401. The reversal of 161040400 is 4040161.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 31899904 + 129140496 = 5648^2 + 11364^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is not an unprimeable number, because it can be changed into a prime (161040401) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 200901 + ... + 201700.

Almost surely, 2^161040400 is an apocalyptic number.

161040400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161040400 is an abundant number, since it is smaller than the sum of its proper divisors (225860122).

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

161040400 is a wasteful number, since it uses less digits than its factorization.

161040400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 402619 (or 402608 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 161040400 is about 12690.1694236129. The cubic root of 161040400 is about 544.0576820324.

Adding to 161040400 its reverse (4040161), we get a palindrome (165080561).

It can be divided in two parts, 16 and 1040400, that multiplied together give a square (16646400 = 4080²).

The spelling of 161040400 in words is "one hundred sixty-one million, forty thousand, four hundred".