999961990 has 16 divisors (see below), whose sum is σ = 1841791248. Its totient is φ = 390682656.

The previous prime is 999961979. The next prime is 999962057. The reversal of 999961990 is 99169999.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1162317 + ... + 1163176.

It is an arithmetic number, because the mean of its divisors is an integer number (115111953).

Almost surely, 2^999961990 is an apocalyptic number.

999961990 is a deficient number, since it is larger than the sum of its proper divisors (841829258).

999961990 is a wasteful number, since it uses less digits than its factorization.

999961990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2325543.

The product of its (nonzero) digits is 3188646, while the sum is 61.

The square root of 999961990 is about 31622.1756051035. The cubic root of 999961990 is about 999.9873298395.

The spelling of 999961990 in words is "nine hundred ninety-nine million, nine hundred sixty-one thousand, nine hundred ninety".