31511256541 has 2 divisors, whose sum is σ = 31511256542. Its totient is φ = 31511256540.

The previous prime is 31511256521. The next prime is 31511256563. The reversal of 31511256541 is 14565211513.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26938656900 + 4572599641 = 164130^2 + 67621^2 .

It is an emirp because it is prime and its reverse (14565211513) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31511256541 - 2¹⁵ = 31511223773 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31511256497 and 31511256506.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31511256521) 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, 15755628270 + 15755628271.

It is an arithmetic number, because the mean of its divisors is an integer number (15755628271).

Almost surely, 2^31511256541 is an apocalyptic number.

It is an amenable number.

31511256541 is a deficient number, since it is larger than the sum of its proper divisors (1).

31511256541 is an equidigital number, since it uses as much as digits as its factorization.

31511256541 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18000, while the sum is 34.

The spelling of 31511256541 in words is "thirty-one billion, five hundred eleven million, two hundred fifty-six thousand, five hundred forty-one".