161686316340 has 36 divisors (see below), whose sum is σ = 490448493444. Its totient is φ = 43116350976.

The previous prime is 161686316329. The next prime is 161686316353. The reversal of 161686316340 is 43613686161.

161686316340 is a `hidden beast` number, since 1 + 6 + 1 + 6 + 8 + 6 + 3 + 1 + 634 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 29930384016 + 131755932324 = 173004^2 + 362982^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×161686316340² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 449128477 + ... + 449128836.

Almost surely, 2^161686316340 is an apocalyptic number.

161686316340 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161686316340 is an abundant number, since it is smaller than the sum of its proper divisors (328762177104).

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

161686316340 is a wasteful number, since it uses less digits than its factorization.

161686316340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 898257328 (or 898257323 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 45.

The spelling of 161686316340 in words is "one hundred sixty-one billion, six hundred eighty-six million, three hundred sixteen thousand, three hundred forty".