161755740 has 72 divisors (see below), whose sum is σ = 516494160. Its totient is φ = 40863744.

The previous prime is 161755729. The next prime is 161755747. The reversal of 161755740 is 47557161.

161755740 is a `hidden beast` number, since 1 + 61 + 7 + 557 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 161755695 and 161755704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161755747) 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, 20229 + ... + 27068.

It is an arithmetic number, because the mean of its divisors is an integer number (7173530).

Almost surely, 2^161755740 is an apocalyptic number.

161755740 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161755740 is an abundant number, since it is smaller than the sum of its proper divisors (354738420).

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

161755740 is a wasteful number, since it uses less digits than its factorization.

161755740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47331 (or 47326 counting only the distinct ones).

The product of its (nonzero) digits is 29400, while the sum is 36.

The square root of 161755740 is about 12718.3230026604. The cubic root of 161755740 is about 544.8620586282.

The spelling of 161755740 in words is "one hundred sixty-one million, seven hundred fifty-five thousand, seven hundred forty".