161664436 has 12 divisors (see below), whose sum is σ = 283166212. Its totient is φ = 80759808.

The previous prime is 161664409. The next prime is 161664439. The reversal of 161664436 is 634466161.

161664436 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 76212900 + 85451536 = 8730^2 + 9244^2 .

It is a super-2 number, since 2×161664436² = 52270779734396192, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 161664395 and 161664404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161664439) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12915 + ... + 22138.

Almost surely, 2^161664436 is an apocalyptic number.

It is an amenable number.

161664436 is a deficient number, since it is larger than the sum of its proper divisors (121501776).

161664436 is a wasteful number, since it uses less digits than its factorization.

161664436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36210 (or 36208 counting only the distinct ones).

The product of its digits is 62208, while the sum is 37.

The square root of 161664436 is about 12714.7330290494. The cubic root of 161664436 is about 544.7595224451.

It can be divided in two parts, 16166 and 4436, that added together give a palindrome (20602).

The spelling of 161664436 in words is "one hundred sixty-one million, six hundred sixty-four thousand, four hundred thirty-six".