21312432225397 has 2 divisors, whose sum is σ = 21312432225398. Its totient is φ = 21312432225396.

The previous prime is 21312432225323. The next prime is 21312432225443. The reversal of 21312432225397 is 79352223421312.

It is an a-pointer prime, because the next prime (21312432225443) can be obtained adding 21312432225397 to its sum of digits (46).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11980085423076 + 9332346802321 = 3461226^2 + 3054889^2 .

It is a cyclic number.

It is not a de Polignac number, because 21312432225397 - 2¹⁵ = 21312432192629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21312432225307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10656216112698 + 10656216112699.

It is an arithmetic number, because the mean of its divisors is an integer number (10656216112699).

Almost surely, 2^{21312432225397} is an apocalyptic number.

It is an amenable number.

21312432225397 is a deficient number, since it is larger than the sum of its proper divisors (1).

21312432225397 is an equidigital number, since it uses as much as digits as its factorization.

21312432225397 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1088640, while the sum is 46.

The spelling of 21312432225397 in words is "twenty-one trillion, three hundred twelve billion, four hundred thirty-two million, two hundred twenty-five thousand, three hundred ninety-seven".