971913987 has 72 divisors (see below), whose sum is σ = 1670131008. Its totient is φ = 542108160.

The previous prime is 971913983. The next prime is 971913991. The reversal of 971913987 is 789319179.

It is an interprime number because it is at equal distance from previous prime (971913983) and next prime (971913991).

It is not a de Polignac number, because 971913987 - 2² = 971913983 is a prime.

It is not an unprimeable number, because it can be changed into a prime (971913983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 869553 + ... + 870669.

It is an arithmetic number, because the mean of its divisors is an integer number (23196264).

Almost surely, 2^971913987 is an apocalyptic number.

971913987 is a deficient number, since it is larger than the sum of its proper divisors (698217021).

971913987 is a wasteful number, since it uses less digits than its factorization.

971913987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1209 (or 1195 counting only the distinct ones).

The product of its digits is 857304, while the sum is 54.

The square root of 971913987 is about 31175.5350715910. The cubic root of 971913987 is about 990.5489548077.

The spelling of 971913987 in words is "nine hundred seventy-one million, nine hundred thirteen thousand, nine hundred eighty-seven".