999989992 has 8 divisors (see below), whose sum is σ = 1874981250. Its totient is φ = 499994992.

The previous prime is 999989981. The next prime is 999990011. The reversal of 999989992 is 299989999.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 791071876 + 208918116 = 28126^2 + 14454^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62499367 + ... + 62499382.

Almost surely, 2^999989992 is an apocalyptic number.

It is an amenable number.

999989992 is a deficient number, since it is larger than the sum of its proper divisors (874991258).

999989992 is a wasteful number, since it uses less digits than its factorization.

999989992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124998755 (or 124998751 counting only the distinct ones).

The product of its digits is 76527504, while the sum is 73.

The square root of 999989992 is about 31622.6183609138. The cubic root of 999989992 is about 999.9966639889.

The spelling of 999989992 in words is "nine hundred ninety-nine million, nine hundred eighty-nine thousand, nine hundred ninety-two".