221220121012 has 24 divisors (see below), whose sum is σ = 422345361312. Its totient is φ = 100550781600.

The previous prime is 221220121009. The next prime is 221220121027. The reversal of 221220121012 is 210121022122.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1308103 + ... + 1467505.

It is an arithmetic number, because the mean of its divisors is an integer number (17597723388).

Almost surely, 2^221220121012 is an apocalyptic number.

221220121012 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

221220121012 is a deficient number, since it is larger than the sum of its proper divisors (201125240300).

221220121012 is a wasteful number, since it uses less digits than its factorization.

221220121012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190959 (or 190957 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 221220121012 its reverse (210121022122), we get a palindrome (431341143134).

The spelling of 221220121012 in words is "two hundred twenty-one billion, two hundred twenty million, one hundred twenty-one thousand, twelve".