9978971 has 4 divisors (see below), whose sum is σ = 10504200. Its totient is φ = 9453744.

The previous prime is 9978961. The next prime is 9978989. The reversal of 9978971 is 1798799.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1798799 = 139 ⋅12941.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9978971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9978911) 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, 262586 + ... + 262623.

It is an arithmetic number, because the mean of its divisors is an integer number (2626050).

Almost surely, 2^9978971 is an apocalyptic number.

9978971 is a deficient number, since it is larger than the sum of its proper divisors (525229).

9978971 is a wasteful number, since it uses less digits than its factorization.

9978971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 525228.

The product of its digits is 285768, while the sum is 50.

The square root of 9978971 is about 3158.9509334588. The cubic root of 9978971 is about 215.2923443300.

The spelling of 9978971 in words is "nine million, nine hundred seventy-eight thousand, nine hundred seventy-one".