1321821355 has 12 divisors (see below), whose sum is σ = 1674065232. Its totient is φ = 1001800080.

The previous prime is 1321821353. The next prime is 1321821379. The reversal of 1321821355 is 5531281231.

It is not a de Polignac number, because 1321821355 - 2¹ = 1321821353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1321821353) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 364351 + ... + 367960.

It is an arithmetic number, because the mean of its divisors is an integer number (139505436).

Almost surely, 2^1321821355 is an apocalyptic number.

1321821355 is a deficient number, since it is larger than the sum of its proper divisors (352243877).

1321821355 is an equidigital number, since it uses as much as digits as its factorization.

1321821355 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 732354 (or 732335 counting only the distinct ones).

The product of its digits is 7200, while the sum is 31.

The square root of 1321821355 is about 36356.8611819007. The cubic root of 1321821355 is about 1097.4656129449.

The spelling of 1321821355 in words is "one billion, three hundred twenty-one million, eight hundred twenty-one thousand, three hundred fifty-five".