31520421022021 has 2 divisors, whose sum is σ = 31520421022022. Its totient is φ = 31520421022020.

The previous prime is 31520421022019. The next prime is 31520421022043. The reversal of 31520421022021 is 12022012402513.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31519679549121 + 741472900 = 5614239^2 + 27230^2 .

It is a cyclic number.

It is not a de Polignac number, because 31520421022021 - 2¹ = 31520421022019 is a prime.

Together with 31520421022019, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31520421022061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15760210511010 + 15760210511011.

It is an arithmetic number, because the mean of its divisors is an integer number (15760210511011).

Almost surely, 2^{31520421022021} is an apocalyptic number.

It is an amenable number.

31520421022021 is a deficient number, since it is larger than the sum of its proper divisors (1).

31520421022021 is an equidigital number, since it uses as much as digits as its factorization.

31520421022021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1920, while the sum is 25.

Adding to 31520421022021 its reverse (12022012402513), we get a palindrome (43542433424534).

The spelling of 31520421022021 in words is "thirty-one trillion, five hundred twenty billion, four hundred twenty-one million, twenty-two thousand, twenty-one".