161258138 has 4 divisors (see below), whose sum is σ = 241887210. Its totient is φ = 80629068.

The previous prime is 161258137. The next prime is 161258147. The reversal of 161258138 is 831852161.

161258138 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 142396489 + 18861649 = 11933^2 + 4343^2 .

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 161258098 and 161258107.

It is not an unprimeable number, because it can be changed into a prime (161258131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40314533 + ... + 40314536.

Almost surely, 2^161258138 is an apocalyptic number.

161258138 is a deficient number, since it is larger than the sum of its proper divisors (80629072).

161258138 is an equidigital number, since it uses as much as digits as its factorization.

161258138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80629071.

The product of its digits is 11520, while the sum is 35.

The square root of 161258138 is about 12698.7455285945. The cubic root of 161258138 is about 544.3027730819.

The spelling of 161258138 in words is "one hundred sixty-one million, two hundred fifty-eight thousand, one hundred thirty-eight".