161236100 has 18 divisors (see below), whose sum is σ = 349882554. Its totient is φ = 64494400.

The previous prime is 161236099. The next prime is 161236129. The reversal of 161236100 is 1632161.

It can be written as a sum of positive squares in 3 ways, for example, as 11075584 + 150160516 = 3328^2 + 12254^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 806081 + ... + 806280.

Almost surely, 2^161236100 is an apocalyptic number.

161236100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161236100 is an abundant number, since it is smaller than the sum of its proper divisors (188646454).

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

161236100 is a wasteful number, since it uses less digits than its factorization.

161236100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1612375 (or 1612368 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 161236100 is about 12697.8777754395. The cubic root of 161236100 is about 544.2779766258.

Adding to 161236100 its reverse (1632161), we get a palindrome (162868261).

The spelling of 161236100 in words is "one hundred sixty-one million, two hundred thirty-six thousand, one hundred".