221358021 has 16 divisors (see below), whose sum is σ = 298821120. Its totient is φ = 145741680.

The previous prime is 221358019. The next prime is 221358043. The reversal of 221358021 is 120853122.

It is not a de Polignac number, because 221358021 - 2¹ = 221358019 is a prime.

It is a super-2 number, since 2×221358021² = 97998746922072882, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 221357982 and 221358000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221358521) 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, 150990 + ... + 152448.

It is an arithmetic number, because the mean of its divisors is an integer number (18676320).

Almost surely, 2^221358021 is an apocalyptic number.

It is an amenable number.

221358021 is a deficient number, since it is larger than the sum of its proper divisors (77463099).

221358021 is a wasteful number, since it uses less digits than its factorization.

221358021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2056.

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 221358021 is about 14878.1054237426. The cubic root of 221358021 is about 604.9206653251.

The spelling of 221358021 in words is "two hundred twenty-one million, three hundred fifty-eight thousand, twenty-one".