1990587890 has 8 divisors (see below), whose sum is σ = 3583058220. Its totient is φ = 796235152.

The previous prime is 1990587887. The next prime is 1990587899. The reversal of 1990587890 is 987850991.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1928351569 + 62236321 = 43913^2 + 7889^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (1990587899) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 99529385 + ... + 99529404.

Almost surely, 2^1990587890 is an apocalyptic number.

1990587890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1990587890 is a deficient number, since it is larger than the sum of its proper divisors (1592470330).

1990587890 is a wasteful number, since it uses less digits than its factorization.

1990587890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199058796.

The product of its (nonzero) digits is 1632960, while the sum is 56.

The square root of 1990587890 is about 44616.0048637258. The cubic root of 1990587890 is about 1257.9415221321.

The spelling of 1990587890 in words is "one billion, nine hundred ninety million, five hundred eighty-seven thousand, eight hundred ninety".