161135640 has 96 divisors (see below), whose sum is σ = 525517200. Its totient is φ = 42819840.

The previous prime is 161135591. The next prime is 161135641. The reversal of 161135640 is 46531161.

161135640 is a `hidden beast` number, since 1 + 6 + 1 + 13 + 5 + 640 = 666.

161135640 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161135641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 135850 + ... + 137030.

Almost surely, 2^161135640 is an apocalyptic number.

161135640 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 161135640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (262758600).

161135640 is an abundant number, since it is smaller than the sum of its proper divisors (364381560).

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

161135640 is a wasteful number, since it uses less digits than its factorization.

161135640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1577 (or 1570 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 161135640 is about 12693.9213799361. The cubic root of 161135640 is about 544.1649135971.

The spelling of 161135640 in words is "one hundred sixty-one million, one hundred thirty-five thousand, six hundred forty".