161520421212 has 18 divisors (see below), whose sum is σ = 408287731488. Its totient is φ = 53840140392.

The previous prime is 161520421211. The next prime is 161520421291. The reversal of 161520421212 is 212124025161.

It is a happy number.

161520421212 is a `hidden beast` number, since 1 + 6 + 1 + 5 + 20 + 421 + 212 = 666.

161520421212 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161520421211) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 2243339148 + ... + 2243339219.

Almost surely, 2^161520421212 is an apocalyptic number.

161520421212 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

161520421212 is an abundant number, since it is smaller than the sum of its proper divisors (246767310276).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161520421212 is a wasteful number, since it uses less digits than its factorization.

161520421212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4486678377 (or 4486678372 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

Adding to 161520421212 its reverse (212124025161), we get a palindrome (373644446373).

The spelling of 161520421212 in words is "one hundred sixty-one billion, five hundred twenty million, four hundred twenty-one thousand, two hundred twelve".