31421300221 has 2 divisors, whose sum is σ = 31421300222. Its totient is φ = 31421300220.

The previous prime is 31421300191. The next prime is 31421300291. The reversal of 31421300221 is 12200312413.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28270723321 + 3150576900 = 168139^2 + 56130^2 .

It is a cyclic number.

It is not a de Polignac number, because 31421300221 - 2¹³ = 31421292029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31421300291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15710650110 + 15710650111.

It is an arithmetic number, because the mean of its divisors is an integer number (15710650111).

Almost surely, 2^31421300221 is an apocalyptic number.

It is an amenable number.

31421300221 is a deficient number, since it is larger than the sum of its proper divisors (1).

31421300221 is an equidigital number, since it uses as much as digits as its factorization.

31421300221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 31421300221 its reverse (12200312413), we get a palindrome (43621612634).

The spelling of 31421300221 in words is "thirty-one billion, four hundred twenty-one million, three hundred thousand, two hundred twenty-one".