1000555221 has 16 divisors (see below), whose sum is σ = 1380008000. Its totient is φ = 644329728.

The previous prime is 1000555207. The next prime is 1000555229. The reversal of 1000555221 is 1225550001.

It is not a de Polignac number, because 1000555221 - 2⁵ = 1000555189 is a prime.

It is a super-2 number, since 2×1000555221² = 2002221500540717682, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1000555229) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16996 + ... + 47853.

It is an arithmetic number, because the mean of its divisors is an integer number (86250500).

Almost surely, 2^1000555221 is an apocalyptic number.

It is an amenable number.

1000555221 is a deficient number, since it is larger than the sum of its proper divisors (379452779).

1000555221 is a wasteful number, since it uses less digits than its factorization.

1000555221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65028.

The product of its (nonzero) digits is 500, while the sum is 21.

The square root of 1000555221 is about 31631.5541983002. The cubic root of 1000555221 is about 1000.1850394250.

The spelling of 1000555221 in words is "one billion, five hundred fifty-five thousand, two hundred twenty-one".