1221042443421 has 8 divisors (see below), whose sum is σ = 1713743780320. Its totient is φ = 771184701072.

The previous prime is 1221042443393. The next prime is 1221042443461. The reversal of 1221042443421 is 1243442401221.

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

It is not a de Polignac number, because 1221042443421 - 2¹¹ = 1221042441373 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221042443461) 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, 10710898570 + ... + 10710898683.

It is an arithmetic number, because the mean of its divisors is an integer number (214217972540).

Almost surely, 2^{1221042443421} is an apocalyptic number.

It is an amenable number.

1221042443421 is a deficient number, since it is larger than the sum of its proper divisors (492701336899).

1221042443421 is a wasteful number, since it uses less digits than its factorization.

1221042443421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21421797275.

The product of its (nonzero) digits is 12288, while the sum is 30.

Adding to 1221042443421 its reverse (1243442401221), we get a palindrome (2464484844642).

The spelling of 1221042443421 in words is "one trillion, two hundred twenty-one billion, forty-two million, four hundred forty-three thousand, four hundred twenty-one".