21000150221 has 2 divisors, whose sum is σ = 21000150222. Its totient is φ = 21000150220.

The previous prime is 21000150217. The next prime is 21000150251. The reversal of 21000150221 is 12205100012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17326456900 + 3673693321 = 131630^2 + 60611^2 .

It is a cyclic number.

It is not a de Polignac number, because 21000150221 - 2² = 21000150217 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21000150196 and 21000150205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21000150211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500075110 + 10500075111.

It is an arithmetic number, because the mean of its divisors is an integer number (10500075111).

Almost surely, 2^21000150221 is an apocalyptic number.

It is an amenable number.

21000150221 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000150221 is an equidigital number, since it uses as much as digits as its factorization.

21000150221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40, while the sum is 14.

Adding to 21000150221 its reverse (12205100012), we get a palindrome (33205250233).

The spelling of 21000150221 in words is "twenty-one billion, one hundred fifty thousand, two hundred twenty-one".