9979747391 has 4 divisors (see below), whose sum is σ = 10027044984. Its totient is φ = 9932449800.

The previous prime is 9979747387. The next prime is 9979747417. The reversal of 9979747391 is 1937479799.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1937479799 = 19 ⋅101972621.

It is a cyclic number.

It is not a de Polignac number, because 9979747391 - 2² = 9979747387 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9979747091) 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, 23648480 + ... + 23648901.

It is an arithmetic number, because the mean of its divisors is an integer number (2506761246).

Almost surely, 2^9979747391 is an apocalyptic number.

9979747391 is a deficient number, since it is larger than the sum of its proper divisors (47297593).

9979747391 is a wasteful number, since it uses less digits than its factorization.

9979747391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47297592.

The product of its digits is 27005076, while the sum is 65.

The square root of 9979747391 is about 99898.6856319942. The cubic root of 9979747391 is about 2152.9792762786.

The spelling of 9979747391 in words is "nine billion, nine hundred seventy-nine million, seven hundred forty-seven thousand, three hundred ninety-one".