1990438713 has 6 divisors (see below), whose sum is σ = 2875078154. Its totient is φ = 1326959136.

The previous prime is 1990438711. The next prime is 1990438721. The reversal of 1990438713 is 3178340991.

It can be written as a sum of positive squares in only one way, i.e., 1492122384 + 498316329 = 38628^2 + 22323^2 .

It is not a de Polignac number, because 1990438713 - 2¹ = 1990438711 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1990438711) 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 in 5 ways as a sum of consecutive naturals, for example, 110579920 + ... + 110579937.

Almost surely, 2^1990438713 is an apocalyptic number.

It is an amenable number.

1990438713 is a deficient number, since it is larger than the sum of its proper divisors (884639441).

1990438713 is a wasteful number, since it uses less digits than its factorization.

1990438713 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221159863 (or 221159860 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 45.

The square root of 1990438713 is about 44614.3330444376. Note that the first 3 decimals coincide. The cubic root of 1990438713 is about 1257.9100974742.

The spelling of 1990438713 in words is "one billion, nine hundred ninety million, four hundred thirty-eight thousand, seven hundred thirteen".