161138109 has 16 divisors (see below), whose sum is σ = 237210624. Its totient is φ = 96481200.

The previous prime is 161138099. The next prime is 161138111. The reversal of 161138109 is 901831161.

It is not a de Polignac number, because 161138109 - 2¹² = 161134013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161138129) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26677 + ... + 32154.

It is an arithmetic number, because the mean of its divisors is an integer number (14825664).

Almost surely, 2^161138109 is an apocalyptic number.

It is an amenable number.

161138109 is a deficient number, since it is larger than the sum of its proper divisors (76072515).

161138109 is a wasteful number, since it uses less digits than its factorization.

161138109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58928.

The product of its (nonzero) digits is 1296, while the sum is 30.

The square root of 161138109 is about 12694.0186308355. The cubic root of 161138109 is about 544.1676929043.

The spelling of 161138109 in words is "one hundred sixty-one million, one hundred thirty-eight thousand, one hundred nine".