999400090 has 36 divisors (see below), whose sum is σ = 1950479514. Its totient is φ = 368529408.

The previous prime is 999400069. The next prime is 999400147. The reversal of 999400090 is 90004999.

999400090 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 9 ways, for example, as 31505769 + 967894321 = 5613^2 + 31111^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1299226 + ... + 1299994.

Almost surely, 2^999400090 is an apocalyptic number.

999400090 is a deficient number, since it is larger than the sum of its proper divisors (951079424).

999400090 is an equidigital number, since it uses as much as digits as its factorization.

999400090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1571 (or 789 counting only the distinct ones).

The product of its (nonzero) digits is 26244, while the sum is 40.

The square root of 999400090 is about 31613.2897687033. The cubic root of 999400090 is about 999.7999899987.

Multiplying 999400090 by its sum of digits (40), we get a square (39976003600 = 199940²).

The spelling of 999400090 in words is "nine hundred ninety-nine million, four hundred thousand, ninety".