1990000399 has 16 divisors (see below), whose sum is σ = 2134162080. Its totient is φ = 1848985600.

The previous prime is 1990000393. The next prime is 1990000421. The reversal of 1990000399 is 9930000991.

It is a cyclic number.

It is not a de Polignac number, because 1990000399 - 2¹⁷ = 1989869327 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1990000393) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 514824 + ... + 518674.

It is an arithmetic number, because the mean of its divisors is an integer number (133385130).

Almost surely, 2^1990000399 is an apocalyptic number.

1990000399 is a deficient number, since it is larger than the sum of its proper divisors (144161681).

1990000399 is a wasteful number, since it uses less digits than its factorization.

1990000399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4250.

The product of its (nonzero) digits is 19683, while the sum is 40.

The square root of 1990000399 is about 44609.4205185407. The cubic root of 1990000399 is about 1257.8177560087.

The spelling of 1990000399 in words is "one billion, nine hundred ninety million, three hundred ninety-nine", and thus it is an aban number.