161640986116 has 27 divisors (see below), whose sum is σ = 289998459093. Its totient is φ = 78833179680.

The previous prime is 161640986113. The next prime is 161640986123. The reversal of 161640986116 is 611689046161.

The square root of 161640986116 is 402046.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 7788768516 + 153852217600 = 88254^2 + 392240^2 .

It is a super-2 number, since 2×161640986116² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 161640986116.

It is not an unprimeable number, because it can be changed into a prime (161640986113) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 32965321 + ... + 32970223.

Almost surely, 2^161640986116 is an apocalyptic number.

161640986116 is the 402046-th square number.

It is an amenable number.

161640986116 is a deficient number, since it is larger than the sum of its proper divisors (128357472977).

161640986116 is an frugal number, since it uses more digits than its factorization.

161640986116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9892 (or 4946 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 49.

Multiplying 161640986116 by its sum of digits (49), we get a square (7920408319684 = 2814322²).

The spelling of 161640986116 in words is "one hundred sixty-one billion, six hundred forty million, nine hundred eighty-six thousand, one hundred sixteen".