971511913 has 2 divisors, whose sum is σ = 971511914. Its totient is φ = 971511912.

The previous prime is 971511911. The next prime is 971511991. The reversal of 971511913 is 319115179.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 703469529 + 268042384 = 26523^2 + 16372^2 .

It is a cyclic number.

It is not a de Polignac number, because 971511913 - 2¹ = 971511911 is a prime.

Together with 971511911, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (971511911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 485755956 + 485755957.

It is an arithmetic number, because the mean of its divisors is an integer number (485755957).

Almost surely, 2^971511913 is an apocalyptic number.

It is an amenable number.

971511913 is a deficient number, since it is larger than the sum of its proper divisors (1).

971511913 is an equidigital number, since it uses as much as digits as its factorization.

971511913 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8505, while the sum is 37.

The square root of 971511913 is about 31169.0858544167. The cubic root of 971511913 is about 990.4123415821.

The spelling of 971511913 in words is "nine hundred seventy-one million, five hundred eleven thousand, nine hundred thirteen".