1990217660 has 12 divisors (see below), whose sum is σ = 4179457128. Its totient is φ = 796087056.

The previous prime is 1990217653. The next prime is 1990217683. The reversal of 1990217660 is 667120991.

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 3 ways as a sum of consecutive naturals, for example, 49755422 + ... + 49755461.

It is an arithmetic number, because the mean of its divisors is an integer number (348288094).

Almost surely, 2^1990217660 is an apocalyptic number.

1990217660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1990217660 is an abundant number, since it is smaller than the sum of its proper divisors (2189239468).

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

1990217660 is a wasteful number, since it uses less digits than its factorization.

1990217660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99510892 (or 99510890 counting only the distinct ones).

The product of its (nonzero) digits is 40824, while the sum is 41.

The square root of 1990217660 is about 44611.8555991566. The cubic root of 1990217660 is about 1257.8635289977.

The spelling of 1990217660 in words is "one billion, nine hundred ninety million, two hundred seventeen thousand, six hundred sixty".