161000020 has 12 divisors (see below), whose sum is σ = 338100084. Its totient is φ = 64400000.

The previous prime is 161000017. The next prime is 161000057. The reversal of 161000020 is 20000161.

It can be written as a sum of positive squares in 2 ways, for example, as 18818244 + 142181776 = 4338^2 + 11924^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 160999970 and 161000006.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4024981 + ... + 4025020.

It is an arithmetic number, because the mean of its divisors is an integer number (28175007).

Almost surely, 2^161000020 is an apocalyptic number.

161000020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161000020 is an abundant number, since it is smaller than the sum of its proper divisors (177100064).

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

161000020 is a wasteful number, since it uses less digits than its factorization.

161000020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8050010 (or 8050008 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 161000020 is about 12688.5783285599. The cubic root of 161000020 is about 544.0122050679.

Adding to 161000020 its reverse (20000161), we get a palindrome (181000181).

The spelling of 161000020 in words is "one hundred sixty-one million, twenty", and thus it is an aban number.