1990020500 has 48 divisors (see below), whose sum is σ = 4680543504. Its totient is φ = 734774400.

The previous prime is 1990020463. The next prime is 1990020511. The reversal of 1990020500 is 50200991.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 1398460816 + 591559684 = 37396^2 + 24322^2 .

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a self number, because there is not a number n which added to its sum of digits gives 1990020500.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 146579 + ... + 159578.

It is an arithmetic number, because the mean of its divisors is an integer number (97511323).

Almost surely, 2^1990020500 is an apocalyptic number.

1990020500 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1990020500 is an abundant number, since it is smaller than the sum of its proper divisors (2690523004).

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

1990020500 is a wasteful number, since it uses less digits than its factorization.

1990020500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 306189 (or 306177 counting only the distinct ones).

The product of its (nonzero) digits is 810, while the sum is 26.

The square root of 1990020500 is about 44609.6458179170. The cubic root of 1990020500 is about 1257.8219910681.

The spelling of 1990020500 in words is "one billion, nine hundred ninety million, twenty thousand, five hundred".