161811626 has 4 divisors (see below), whose sum is σ = 242717442. Its totient is φ = 80905812.

The previous prime is 161811583. The next prime is 161811641. The reversal of 161811626 is 626118161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 626118161 = 47 ⋅13321663.

It can be written as a sum of positive squares in only one way, i.e., 148815601 + 12996025 = 12199^2 + 3605^2 .

It is a junction number, because it is equal to n+sod(n) for n = 161811592 and 161811601.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40452905 + ... + 40452908.

Almost surely, 2^161811626 is an apocalyptic number.

161811626 is a deficient number, since it is larger than the sum of its proper divisors (80905816).

161811626 is an equidigital number, since it uses as much as digits as its factorization.

161811626 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80905815.

The product of its digits is 3456, while the sum is 32.

The square root of 161811626 is about 12720.5198793131. The cubic root of 161811626 is about 544.9248006673.

Adding to 161811626 its reverse (626118161), we get a palindrome (787929787).

The spelling of 161811626 in words is "one hundred sixty-one million, eight hundred eleven thousand, six hundred twenty-six".