31540215373 has 2 divisors, whose sum is σ = 31540215374. Its totient is φ = 31540215372.

The previous prime is 31540215313. The next prime is 31540215397. The reversal of 31540215373 is 37351204513.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17239164804 + 14301050569 = 131298^2 + 119587^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31540215373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31540215313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15770107686 + 15770107687.

It is an arithmetic number, because the mean of its divisors is an integer number (15770107687).

Almost surely, 2^31540215373 is an apocalyptic number.

It is an amenable number.

31540215373 is a deficient number, since it is larger than the sum of its proper divisors (1).

31540215373 is an equidigital number, since it uses as much as digits as its factorization.

31540215373 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 37800, while the sum is 34.

Adding to 31540215373 its reverse (37351204513), we get a palindrome (68891419886).

The spelling of 31540215373 in words is "thirty-one billion, five hundred forty million, two hundred fifteen thousand, three hundred seventy-three".