31618145381 has 2 divisors, whose sum is σ = 31618145382. Its totient is φ = 31618145380.

The previous prime is 31618145297. The next prime is 31618145399. The reversal of 31618145381 is 18354181613.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19833088900 + 11785056481 = 140830^2 + 108559^2 .

It is a cyclic number.

It is not a de Polignac number, because 31618145381 - 2¹⁸ = 31617883237 is a prime.

It is a super-2 number, since 2×31618145381² (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 (31618145281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15809072690 + 15809072691.

It is an arithmetic number, because the mean of its divisors is an integer number (15809072691).

Almost surely, 2^31618145381 is an apocalyptic number.

It is an amenable number.

31618145381 is a deficient number, since it is larger than the sum of its proper divisors (1).

31618145381 is an equidigital number, since it uses as much as digits as its factorization.

31618145381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 69120, while the sum is 41.

The spelling of 31618145381 in words is "thirty-one billion, six hundred eighteen million, one hundred forty-five thousand, three hundred eighty-one".