999979999897 has 4 divisors (see below), whose sum is σ = 1005967904256. Its totient is φ = 993992095540.

The previous prime is 999979999873. The next prime is 999979999951. The reversal of 999979999897 is 798999979999.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-999979999897 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 999979999796 and 999979999805.

It is not an unprimeable number, because it can be changed into a prime (999979949897) 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, 2993951929 + ... + 2993952262.

It is an arithmetic number, because the mean of its divisors is an integer number (251491976064).

Almost surely, 2^999979999897 is an apocalyptic number.

It is an amenable number.

999979999897 is a deficient number, since it is larger than the sum of its proper divisors (5987904359).

999979999897 is a wasteful number, since it uses less digits than its factorization.

999979999897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5987904358.

The product of its digits is 151868831688, while the sum is 103.

The spelling of 999979999897 in words is "nine hundred ninety-nine billion, nine hundred seventy-nine million, nine hundred ninety-nine thousand, eight hundred ninety-seven".