161099040 has 96 divisors (see below), whose sum is σ = 512640576. Its totient is φ = 42521600.

The previous prime is 161099017. The next prime is 161099041. The reversal of 161099040 is 40990161.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 161098989 and 161099007.

It is not an unprimeable number, because it can be changed into a prime (161099041) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 46819 + ... + 50141.

It is an arithmetic number, because the mean of its divisors is an integer number (5340006).

Almost surely, 2^161099040 is an apocalyptic number.

161099040 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 161099040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (256320288).

161099040 is an abundant number, since it is smaller than the sum of its proper divisors (351541536).

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

161099040 is a wasteful number, since it uses less digits than its factorization.

161099040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3442 (or 3434 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 161099040 is about 12692.4796631706. The cubic root of 161099040 is about 544.1237103310.

The spelling of 161099040 in words is "one hundred sixty-one million, ninety-nine thousand, forty".