31541323381 has 2 divisors, whose sum is σ = 31541323382. Its totient is φ = 31541323380.

The previous prime is 31541323343. The next prime is 31541323403. The reversal of 31541323381 is 18332314513.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31058422756 + 482900625 = 176234^2 + 21975^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31541323381 is a prime.

It is a super-2 number, since 2×31541323381² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31541323181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15770661690 + 15770661691.

It is an arithmetic number, because the mean of its divisors is an integer number (15770661691).

Almost surely, 2^31541323381 is an apocalyptic number.

It is an amenable number.

31541323381 is a deficient number, since it is larger than the sum of its proper divisors (1).

31541323381 is an equidigital number, since it uses as much as digits as its factorization.

31541323381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25920, while the sum is 34.

Adding to 31541323381 its reverse (18332314513), we get a palindrome (49873637894).

It can be divided in two parts, 3154132 and 3381, that added together give a palindrome (3157513).

The spelling of 31541323381 in words is "thirty-one billion, five hundred forty-one million, three hundred twenty-three thousand, three hundred eighty-one".