1990556517 has 16 divisors (see below), whose sum is σ = 2668037120. Its totient is φ = 1320073200.

The previous prime is 1990556507. The next prime is 1990556539. The reversal of 1990556517 is 7156550991.

It is not a de Polignac number, because 1990556517 - 2⁴ = 1990556501 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1990556507) 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 15 ways as a sum of consecutive naturals, for example, 657834 + ... + 660852.

It is an arithmetic number, because the mean of its divisors is an integer number (166752320).

Almost surely, 2^1990556517 is an apocalyptic number.

It is an amenable number.

1990556517 is a deficient number, since it is larger than the sum of its proper divisors (677480603).

1990556517 is a wasteful number, since it uses less digits than its factorization.

1990556517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4104.

The product of its (nonzero) digits is 425250, while the sum is 48.

The square root of 1990556517 is about 44615.6532732627. The cubic root of 1990556517 is about 1257.9349134301.

The spelling of 1990556517 in words is "one billion, nine hundred ninety million, five hundred fifty-six thousand, five hundred seventeen".