31230000021173 has 2 divisors, whose sum is σ = 31230000021174. Its totient is φ = 31230000021172.

The previous prime is 31230000021169. The next prime is 31230000021193. The reversal of 31230000021173 is 37112000003213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30402233047684 + 827766973489 = 5513822^2 + 909817^2 .

It is a cyclic number.

It is not a de Polignac number, because 31230000021173 - 2² = 31230000021169 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31230000021193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15615000010586 + 15615000010587.

It is an arithmetic number, because the mean of its divisors is an integer number (15615000010587).

Almost surely, 2^{31230000021173} is an apocalyptic number.

It is an amenable number.

31230000021173 is a deficient number, since it is larger than the sum of its proper divisors (1).

31230000021173 is an equidigital number, since it uses as much as digits as its factorization.

31230000021173 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 756, while the sum is 23.

Adding to 31230000021173 its reverse (37112000003213), we get a palindrome (68342000024386).

The spelling of 31230000021173 in words is "thirty-one trillion, two hundred thirty billion, twenty-one thousand, one hundred seventy-three".