1221202221012 has 36 divisors (see below), whose sum is σ = 3086977338900. Its totient is φ = 407060879232.

The previous prime is 1221202220969. The next prime is 1221202221047. The reversal of 1221202221012 is 2101222021221.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 933921228816 + 287280992196 = 966396^2 + 535986^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2350498 + ... + 2822630.

It is an arithmetic number, because the mean of its divisors is an integer number (85749370525).

Almost surely, 2^{1221202221012} is an apocalyptic number.

1221202221012 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1221202221012 is an abundant number, since it is smaller than the sum of its proper divisors (1865775117888).

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

1221202221012 is a wasteful number, since it uses less digits than its factorization.

1221202221012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 543992 (or 543987 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 1221202221012 its reverse (2101222021221), we get a palindrome (3322424242233).

The spelling of 1221202221012 in words is "one trillion, two hundred twenty-one billion, two hundred two million, two hundred twenty-one thousand, twelve".