221020001009 has 2 divisors, whose sum is σ = 221020001010. Its totient is φ = 221020001008.

The previous prime is 221020000997. The next prime is 221020001051. The reversal of 221020001009 is 900100020122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 129525850609 + 91494150400 = 359897^2 + 302480^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221020001009 is a prime.

It is a super-2 number, since 2×221020001009² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (221020001309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110510000504 + 110510000505.

It is an arithmetic number, because the mean of its divisors is an integer number (110510000505).

Almost surely, 2^221020001009 is an apocalyptic number.

It is an amenable number.

221020001009 is a deficient number, since it is larger than the sum of its proper divisors (1).

221020001009 is an equidigital number, since it uses as much as digits as its factorization.

221020001009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 17.

The spelling of 221020001009 in words is "two hundred twenty-one billion, twenty million, one thousand, nine".