161139554 has 4 divisors (see below), whose sum is σ = 241709334. Its totient is φ = 80569776.

The previous prime is 161139527. The next prime is 161139607. The reversal of 161139554 is 455931161.

161139554 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., 145323025 + 15816529 = 12055^2 + 3977^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40284887 + ... + 40284890.

Almost surely, 2^161139554 is an apocalyptic number.

161139554 is a deficient number, since it is larger than the sum of its proper divisors (80569780).

161139554 is an equidigital number, since it uses as much as digits as its factorization.

161139554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80569779.

The product of its digits is 16200, while the sum is 35.

The square root of 161139554 is about 12694.0755472780. The cubic root of 161139554 is about 544.1693195006.

The spelling of 161139554 in words is "one hundred sixty-one million, one hundred thirty-nine thousand, five hundred fifty-four".