491990551599 has 8 divisors (see below), whose sum is σ = 655990650112. Its totient is φ = 327992077080.

The previous prime is 491990551589. The next prime is 491990551609. The reversal of 491990551599 is 995155099194.

It is an interprime number because it is at equal distance from previous prime (491990551589) and next prime (491990551609).

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

It is not a de Polignac number, because 491990551599 - 2⁵ = 491990551567 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 (491990551589) 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 7 ways as a sum of consecutive naturals, for example, 913752 + ... + 1348674.

It is an arithmetic number, because the mean of its divisors is an integer number (81998831264).

Almost surely, 2^491990551599 is an apocalyptic number.

491990551599 is a deficient number, since it is larger than the sum of its proper divisors (164000098513).

491990551599 is a wasteful number, since it uses less digits than its factorization.

491990551599 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 811997.

The product of its (nonzero) digits is 29524500, while the sum is 66.

The spelling of 491990551599 in words is "four hundred ninety-one billion, nine hundred ninety million, five hundred fifty-one thousand, five hundred ninety-nine".