165716340426 has 320 divisors, whose sum is σ = 492295372800. Its totient is φ = 40439274624.

The previous prime is 165716340421. The next prime is 165716340437. The reversal of 165716340426 is 624043617561.

165716340426 is a `hidden beast` number, since 1 + 6 + 5 + 7 + 1 + 634 + 0 + 4 + 2 + 6 = 666.

It is a super-2 number, since 2×165716340426² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (165716340421) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 12037335 + ... + 12051093.

It is an arithmetic number, because the mean of its divisors is an integer number (1538423040).

Almost surely, 2^165716340426 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 165716340426, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (246147686400).

165716340426 is an abundant number, since it is smaller than the sum of its proper divisors (326579032374).

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

165716340426 is a wasteful number, since it uses less digits than its factorization.

165716340426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13855 (or 13846 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 45.

Adding to 165716340426 its reverse (624043617561), we get a palindrome (789759957987).

The spelling of 165716340426 in words is "one hundred sixty-five billion, seven hundred sixteen million, three hundred forty thousand, four hundred twenty-six".