971999999 has 4 divisors (see below), whose sum is σ = 972882336. Its totient is φ = 971117664.

The previous prime is 971999921. The next prime is 972000017. The reversal of 971999999 is 999999179.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 999999179 = 1063 ⋅940733.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-971999999 is a prime.

It is a Duffinian number.

971999999 is a modest number, since divided by 99999 gives 9719 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (971999909) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 439514 + ... + 441719.

It is an arithmetic number, because the mean of its divisors is an integer number (243220584).

Almost surely, 2^971999999 is an apocalyptic number.

971999999 is a deficient number, since it is larger than the sum of its proper divisors (882337).

971999999 is a wasteful number, since it uses less digits than its factorization.

971999999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 882336.

The product of its digits is 33480783, while the sum is 71.

The square root of 971999999 is about 31176.9145202023. The cubic root of 971999999 is about 990.5781743287.

The spelling of 971999999 in words is "nine hundred seventy-one million, nine hundred ninety-nine thousand, nine hundred ninety-nine".