9999397951 has 4 divisors (see below), whose sum is σ = 10000065600. Its totient is φ = 9998730304.

The previous prime is 9999397931. The next prime is 9999397973. The reversal of 9999397951 is 1597939999.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1597939999 = 8111 ⋅197009.

It is a cyclic number.

It is not a de Polignac number, because 9999397951 - 2⁷ = 9999397823 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 (9999397931) 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, 310831 + ... + 341488.

It is an arithmetic number, because the mean of its divisors is an integer number (2500016400).

Almost surely, 2^9999397951 is an apocalyptic number.

9999397951 is a deficient number, since it is larger than the sum of its proper divisors (667649).

9999397951 is a wasteful number, since it uses less digits than its factorization.

9999397951 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 667648.

The product of its digits is 55801305, while the sum is 70.

The square root of 9999397951 is about 99996.9897096908. The cubic root of 9999397951 is about 2154.3914533225.

The spelling of 9999397951 in words is "nine billion, nine hundred ninety-nine million, three hundred ninety-seven thousand, nine hundred fifty-one".