999915970 has 16 divisors (see below), whose sum is σ = 1801268280. Its totient is φ = 399650944.

The previous prime is 999915947. The next prime is 999915971. The reversal of 999915970 is 79519999.

It can be written as a sum of positive squares in 4 ways, for example, as 998623201 + 1292769 = 31601^2 + 1137^2 .

It is a super-2 number, since 2×999915970² = 1999663894122081800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (999915971) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25897 + ... + 51676.

Almost surely, 2^999915970 is an apocalyptic number.

999915970 is a deficient number, since it is larger than the sum of its proper divisors (801352310).

999915970 is a wasteful number, since it uses less digits than its factorization.

999915970 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78869.

The product of its (nonzero) digits is 2066715, while the sum is 58.

The square root of 999915970 is about 31621.4479428125. The cubic root of 999915970 is about 999.9719892154.

The spelling of 999915970 in words is "nine hundred ninety-nine million, nine hundred fifteen thousand, nine hundred seventy".