1990638810 has 36 divisors (see below), whose sum is σ = 5176761642. Its totient is φ = 530724144.

The previous prime is 1990638791. The next prime is 1990638821. The reversal of 1990638810 is 188360991.

1990638810 is a `hidden beast` number, since 1 + 9 + 9 + 0 + 638 + 8 + 1 + 0 = 666.

1990638810 is digitally balanced in base 6, 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 only one way, i.e., 1791574929 + 199063881 = 42327^2 + 14109^2 .

It is a super-2 number, since 2×1990638810² = 7925285743756432200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

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 17 ways as a sum of consecutive naturals, for example, 420919 + ... + 425621.

Almost surely, 2^1990638810 is an apocalyptic number.

1990638810 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1990638810 is an abundant number, since it is smaller than the sum of its proper divisors (3186122832).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1990638810 is an frugal number, since it uses more digits than its factorization.

1990638810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9419 (or 4713 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The square root of 1990638810 is about 44616.5755073157. The cubic root of 1990638810 is about 1257.9522482492.

The spelling of 1990638810 in words is "one billion, nine hundred ninety million, six hundred thirty-eight thousand, eight hundred ten".