1321021221 has 8 divisors (see below), whose sum is σ = 1896851040. Its totient is φ = 812936112.

The previous prime is 1321021217. The next prime is 1321021223. The reversal of 1321021221 is 1221201231.

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

It is not a de Polignac number, because 1321021221 - 2² = 1321021217 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1321021221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321021223) 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, 16936131 + ... + 16936208.

It is an arithmetic number, because the mean of its divisors is an integer number (237106380).

Almost surely, 2^1321021221 is an apocalyptic number.

It is an amenable number.

1321021221 is a deficient number, since it is larger than the sum of its proper divisors (575829819).

1321021221 is a wasteful number, since it uses less digits than its factorization.

1321021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33872355.

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 1321021221 is about 36345.8556234408. The cubic root of 1321021221 is about 1097.2441264356.

Adding to 1321021221 its reverse (1221201231), we get a palindrome (2542222452).

The spelling of 1321021221 in words is "one billion, three hundred twenty-one million, twenty-one thousand, two hundred twenty-one".