161638735 has 4 divisors (see below), whose sum is σ = 193966488. Its totient is φ = 129310984.

The previous prime is 161638727. The next prime is 161638747. The reversal of 161638735 is 537836161.

It is a happy number.

161638735 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, and also an emirpimes, since its reverse is a distinct semiprime: 537836161 = 337 ⋅1595953.

It is a cyclic number.

It is not a de Polignac number, because 161638735 - 2³ = 161638727 is a prime.

It is a super-2 number, since 2×161638735² = 52254161304800450, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16163869 + ... + 16163878.

It is an arithmetic number, because the mean of its divisors is an integer number (48491622).

Almost surely, 2^161638735 is an apocalyptic number.

161638735 is a deficient number, since it is larger than the sum of its proper divisors (32327753).

161638735 is an equidigital number, since it uses as much as digits as its factorization.

161638735 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32327752.

The product of its digits is 90720, while the sum is 40.

The square root of 161638735 is about 12713.7223109521. The cubic root of 161638735 is about 544.7306527550.

The spelling of 161638735 in words is "one hundred sixty-one million, six hundred thirty-eight thousand, seven hundred thirty-five".