31540181693 has 2 divisors, whose sum is σ = 31540181694. Its totient is φ = 31540181692.

The previous prime is 31540181677. The next prime is 31540181731. The reversal of 31540181693 is 39618104513.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27141574009 + 4398607684 = 164747^2 + 66322^2 .

It is a cyclic number.

It is not a de Polignac number, because 31540181693 - 2⁴ = 31540181677 is a prime.

It is a super-2 number, since 2×31540181693² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 31540181693.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31540181633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15770090846 + 15770090847.

It is an arithmetic number, because the mean of its divisors is an integer number (15770090847).

Almost surely, 2^31540181693 is an apocalyptic number.

It is an amenable number.

31540181693 is a deficient number, since it is larger than the sum of its proper divisors (1).

31540181693 is an equidigital number, since it uses as much as digits as its factorization.

31540181693 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 77760, while the sum is 41.

The spelling of 31540181693 in words is "thirty-one billion, five hundred forty million, one hundred eighty-one thousand, six hundred ninety-three".