2855821221 has 24 divisors (see below), whose sum is σ = 4604741856. Its totient is φ = 1690547040.

The previous prime is 2855821219. The next prime is 2855821223. The reversal of 2855821221 is 1221285582.

It is an interprime number because it is at equal distance from previous prime (2855821219) and next prime (2855821223).

It is not a de Polignac number, because 2855821221 - 2¹ = 2855821219 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2855821223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 331170 + ... + 339683.

It is an arithmetic number, because the mean of its divisors is an integer number (191864244).

Almost surely, 2^2855821221 is an apocalyptic number.

It is an amenable number.

2855821221 is a deficient number, since it is larger than the sum of its proper divisors (1748920635).

2855821221 is a wasteful number, since it uses less digits than its factorization.

2855821221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 670913 (or 670910 counting only the distinct ones).

The product of its digits is 25600, while the sum is 36.

The square root of 2855821221 is about 53439.8841783925. The cubic root of 2855821221 is about 1418.7645839199.

The spelling of 2855821221 in words is "two billion, eight hundred fifty-five million, eight hundred twenty-one thousand, two hundred twenty-one".