15505204221212 has 12 divisors (see below), whose sum is σ = 27138624510480. Its totient is φ = 7751311503936.

The previous prime is 15505204221209. The next prime is 15505204221223. The reversal of 15505204221212 is 21212240250551.

It is a super-2 number, since 2×15505204221212² (a number of 27 digits) contains 22 as substring.

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, 322624637 + ... + 322672692.

It is an arithmetic number, because the mean of its divisors is an integer number (2261552042540).

Almost surely, 2^{15505204221212} is an apocalyptic number.

It is an amenable number.

15505204221212 is a deficient number, since it is larger than the sum of its proper divisors (11633420289268).

15505204221212 is a wasteful number, since it uses less digits than its factorization.

15505204221212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 645303340 (or 645303338 counting only the distinct ones).

The product of its (nonzero) digits is 16000, while the sum is 32.

Adding to 15505204221212 its reverse (21212240250551), we get a palindrome (36717444471763).

The spelling of 15505204221212 in words is "fifteen trillion, five hundred five billion, two hundred four million, two hundred twenty-one thousand, two hundred twelve".