1042401021221 has 24 divisors (see below), whose sum is σ = 1235397543840. Its totient is φ = 876735673632.

The previous prime is 1042401021197. The next prime is 1042401021223. The reversal of 1042401021221 is 1221201042401.

It is not a de Polignac number, because 1042401021221 - 2¹⁸ = 1042400759077 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1042401021193 and 1042401021202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1042401021223) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1251791 + ... + 1910963.

It is an arithmetic number, because the mean of its divisors is an integer number (51474897660).

Almost surely, 2^{1042401021221} is an apocalyptic number.

It is an amenable number.

1042401021221 is a deficient number, since it is larger than the sum of its proper divisors (192996522619).

1042401021221 is an equidigital number, since it uses as much as digits as its factorization.

1042401021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 659793 (or 659786 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 1042401021221 its reverse (1221201042401), we get a palindrome (2263602063622).

The spelling of 1042401021221 in words is "one trillion, forty-two billion, four hundred one million, twenty-one thousand, two hundred twenty-one".