999979561 has 8 divisors (see below), whose sum is σ = 1143399104. Its totient is φ = 856701360.

The previous prime is 999979553. The next prime is 999979571. The reversal of 999979561 is 165979999.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 999979561 - 2³ = 999979553 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 999979493 and 999979502.

It is not an unprimeable number, because it can be changed into a prime (999979511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19710 + ... + 48871.

It is an arithmetic number, because the mean of its divisors is an integer number (142924888).

Almost surely, 2^999979561 is an apocalyptic number.

It is an amenable number.

999979561 is a deficient number, since it is larger than the sum of its proper divisors (143419543).

999979561 is a wasteful number, since it uses less digits than its factorization.

999979561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70671.

The product of its digits is 12400290, while the sum is 64.

The square root of 999979561 is about 31622.4534310670. The cubic root of 999979561 is about 999.9931869536.

The spelling of 999979561 in words is "nine hundred ninety-nine million, nine hundred seventy-nine thousand, five hundred sixty-one".