161212405 has 16 divisors (see below), whose sum is σ = 202207104. Its totient is φ = 123154240.

The previous prime is 161212393. The next prime is 161212423. The reversal of 161212405 is 504212161.

It is not a de Polignac number, because 161212405 - 2⁷ = 161212277 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 135222 + ... + 136408.

It is an arithmetic number, because the mean of its divisors is an integer number (12637944).

Almost surely, 2^161212405 is an apocalyptic number.

It is an amenable number.

161212405 is a deficient number, since it is larger than the sum of its proper divisors (40994699).

161212405 is a wasteful number, since it uses less digits than its factorization.

161212405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2396.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 161212405 is about 12696.9447112288. The cubic root of 161212405 is about 544.2513132453.

Adding to 161212405 its reverse (504212161), we get a palindrome (665424566).

The spelling of 161212405 in words is "one hundred sixty-one million, two hundred twelve thousand, four hundred five".