31643375855449 has 2 divisors, whose sum is σ = 31643375855450. Its totient is φ = 31643375855448.

The previous prime is 31643375855447. The next prime is 31643375855459. The reversal of 31643375855449 is 94455857334613.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30838530030025 + 804845825424 = 5553245^2 + 897132^2 .

It is a cyclic number.

It is not a de Polignac number, because 31643375855449 - 2¹ = 31643375855447 is a prime.

Together with 31643375855447, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (31643375855447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15821687927724 + 15821687927725.

It is an arithmetic number, because the mean of its divisors is an integer number (15821687927725).

Almost surely, 2^{31643375855449} is an apocalyptic number.

It is an amenable number.

31643375855449 is a deficient number, since it is larger than the sum of its proper divisors (1).

31643375855449 is an equidigital number, since it uses as much as digits as its factorization.

31643375855449 is an evil number, because the sum of its binary digits is even.

The product of its digits is 653184000, while the sum is 67.

The spelling of 31643375855449 in words is "thirty-one trillion, six hundred forty-three billion, three hundred seventy-five million, eight hundred fifty-five thousand, four hundred forty-nine".