1990633387 has 2 divisors, whose sum is σ = 1990633388. Its totient is φ = 1990633386.

The previous prime is 1990633327. The next prime is 1990633429. The reversal of 1990633387 is 7833360991.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1990633387 - 2⁷ = 1990633259 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1990633387.

It is not a weakly prime, because it can be changed into another prime (1990633327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 995316693 + 995316694.

It is an arithmetic number, because the mean of its divisors is an integer number (995316694).

Almost surely, 2^1990633387 is an apocalyptic number.

1990633387 is a deficient number, since it is larger than the sum of its proper divisors (1).

1990633387 is an equidigital number, since it uses as much as digits as its factorization.

1990633387 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 734832, while the sum is 49.

The square root of 1990633387 is about 44616.5147338965. The cubic root of 1990633387 is about 1257.9511059222.

The spelling of 1990633387 in words is "one billion, nine hundred ninety million, six hundred thirty-three thousand, three hundred eighty-seven".