999917970 has 64 divisors (see below), whose sum is σ = 2549733120. Its totient is φ = 250483968.

The previous prime is 999917969. The next prime is 999917977. The reversal of 999917970 is 79719999.

999917970 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (999917977) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16659 + ... + 47721.

It is an arithmetic number, because the mean of its divisors is an integer number (39839580).

Almost surely, 2^999917970 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 999917970, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1274866560).

999917970 is an abundant number, since it is smaller than the sum of its proper divisors (1549815150).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

999917970 is a wasteful number, since it uses less digits than its factorization.

999917970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31139.

The product of its (nonzero) digits is 2893401, while the sum is 60.

The square root of 999917970 is about 31621.4795669020. The cubic root of 999917970 is about 999.9726559190.

The spelling of 999917970 in words is "nine hundred ninety-nine million, nine hundred seventeen thousand, nine hundred seventy".