161399690000 has 50 divisors (see below), whose sum is σ = 390764813670. Its totient is φ = 64559872000.

The previous prime is 161399689963. The next prime is 161399690017. The reversal of 161399690000 is 96993161.

It is a happy number.

It can be written as a sum of positive squares in 5 ways, for example, as 34982465296 + 126417224704 = 187036^2 + 355552^2 .

It is a tau number, because it is divible by the number of its divisors (50).

It is a super-2 number, since 2×161399690000² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 8059985 + ... + 8079984.

Almost surely, 2^161399690000 is an apocalyptic number.

161399690000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161399690000 is an abundant number, since it is smaller than the sum of its proper divisors (229365123670).

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

161399690000 is an equidigital number, since it uses as much as digits as its factorization.

161399690000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16139997 (or 16139976 counting only the distinct ones).

The product of its (nonzero) digits is 78732, while the sum is 44.

The spelling of 161399690000 in words is "one hundred sixty-one billion, three hundred ninety-nine million, six hundred ninety thousand".