971724991 has 2 divisors, whose sum is σ = 971724992. Its totient is φ = 971724990.

The previous prime is 971724983. The next prime is 971724997. The reversal of 971724991 is 199427179.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 971724991 - 2³ = 971724983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (971724997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 485862495 + 485862496.

It is an arithmetic number, because the mean of its divisors is an integer number (485862496).

Almost surely, 2^971724991 is an apocalyptic number.

971724991 is a deficient number, since it is larger than the sum of its proper divisors (1).

971724991 is an equidigital number, since it uses as much as digits as its factorization.

971724991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 285768, while the sum is 49.

The square root of 971724991 is about 31172.5037653378. The cubic root of 971724991 is about 990.4847440754.

The spelling of 971724991 in words is "nine hundred seventy-one million, seven hundred twenty-four thousand, nine hundred ninety-one".