9979211657 has 4 divisors (see below), whose sum is σ = 10052052756. Its totient is φ = 9906370560.

The previous prime is 9979211623. The next prime is 9979211677. The reversal of 9979211657 is 7561129799.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7561129799 = 397 ⋅19045667.

It can be written as a sum of positive squares in 2 ways, for example, as 5858983936 + 4120227721 = 76544^2 + 64189^2 .

It is a cyclic number.

It is not a de Polignac number, because 9979211657 - 2²⁴ = 9962434441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9979211677) 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, 36420344 + ... + 36420617.

It is an arithmetic number, because the mean of its divisors is an integer number (2513013189).

Almost surely, 2^9979211657 is an apocalyptic number.

It is an amenable number.

9979211657 is a deficient number, since it is larger than the sum of its proper divisors (72841099).

9979211657 is a wasteful number, since it uses less digits than its factorization.

9979211657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72841098.

The product of its digits is 2143260, while the sum is 56.

The square root of 9979211657 is about 99896.0042093777. The cubic root of 9979211657 is about 2152.9407500917.

The spelling of 9979211657 in words is "nine billion, nine hundred seventy-nine million, two hundred eleven thousand, six hundred fifty-seven".