221021020001 has 2 divisors, whose sum is σ = 221021020002. Its totient is φ = 221021020000.

The previous prime is 221021019979. The next prime is 221021020009. The reversal of 221021020001 is 100020120122.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 122063589376 + 98957430625 = 349376^2 + 314575^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221021020001 is a prime.

It is not a weakly prime, because it can be changed into another prime (221021020009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110510510000 + 110510510001.

It is an arithmetic number, because the mean of its divisors is an integer number (110510510001).

Almost surely, 2^221021020001 is an apocalyptic number.

It is an amenable number.

221021020001 is a deficient number, since it is larger than the sum of its proper divisors (1).

221021020001 is an equidigital number, since it uses as much as digits as its factorization.

221021020001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 221021020001 its reverse (100020120122), we get a palindrome (321041140123).

The spelling of 221021020001 in words is "two hundred twenty-one billion, twenty-one million, twenty thousand, one".