1221212002021 has 8 divisors (see below), whose sum is σ = 1332280404000. Its totient is φ = 1110151788240.

The previous prime is 1221212001991. The next prime is 1221212002027. The reversal of 1221212002021 is 1202002121221.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-1221212002021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221212001986 and 1221212002004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221212002027) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1733106 + ... + 2333683.

It is an arithmetic number, because the mean of its divisors is an integer number (166535050500).

Almost surely, 2^{1221212002021} is an apocalyptic number.

1221212002021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221212002021 is a deficient number, since it is larger than the sum of its proper divisors (111068401979).

1221212002021 is a wasteful number, since it uses less digits than its factorization.

1221212002021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4094099.

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

Adding to 1221212002021 its reverse (1202002121221), we get a palindrome (2423214123242).

The spelling of 1221212002021 in words is "one trillion, two hundred twenty-one billion, two hundred twelve million, two thousand, twenty-one".