221998005 has 12 divisors (see below), whose sum is σ = 384796620. Its totient is φ = 118398912.

The previous prime is 221997991. The next prime is 221998027. The reversal of 221998005 is 500899122.

It can be written as a sum of positive squares in 2 ways, for example, as 67667076 + 154330929 = 8226^2 + 12423^2 .

It is not a de Polignac number, because 221998005 - 2¹⁰ = 221996981 is a prime.

It is a super-2 number, since 2×221998005² = 98566228447960050, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2466600 + ... + 2466689.

It is an arithmetic number, because the mean of its divisors is an integer number (32066385).

Almost surely, 2^221998005 is an apocalyptic number.

It is an amenable number.

221998005 is a deficient number, since it is larger than the sum of its proper divisors (162798615).

221998005 is a wasteful number, since it uses less digits than its factorization.

221998005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4933300 (or 4933297 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 221998005 is about 14899.5974777844. The cubic root of 221998005 is about 605.5030808585.

The spelling of 221998005 in words is "two hundred twenty-one million, nine hundred ninety-eight thousand, five".