221000203021 has 6 divisors (see below), whose sum is σ = 239307912330. Its totient is φ = 204000187248.

The previous prime is 221000203009. The next prime is 221000203037. The reversal of 221000203021 is 120302000122.

It can be written as a sum of positive squares in 3 ways, for example, as 3219314121 + 217780888900 = 56739^2 + 466670^2 .

It is not a de Polignac number, because 221000203021 - 2²⁵ = 220966648589 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221000202992 and 221000203010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221000203621) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 653846586 + ... + 653846923.

It is an arithmetic number, because the mean of its divisors is an integer number (39884652055).

Almost surely, 2^221000203021 is an apocalyptic number.

It is an amenable number.

221000203021 is a deficient number, since it is larger than the sum of its proper divisors (18307709309).

221000203021 is a wasteful number, since it uses less digits than its factorization.

221000203021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1307693535 (or 1307693522 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

Adding to 221000203021 its reverse (120302000122), we get a palindrome (341302203143).

The spelling of 221000203021 in words is "two hundred twenty-one billion, two hundred three thousand, twenty-one".