650390987991 has 4 divisors (see below), whose sum is σ = 867187983992. Its totient is φ = 433593991992.

The previous prime is 650390987977. The next prime is 650390988001. The reversal of 650390987991 is 199789093056.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 650390987991 - 2⁹ = 650390987479 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 (650390987941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 108398497996 + ... + 108398498001.

It is an arithmetic number, because the mean of its divisors is an integer number (216796995998).

Almost surely, 2^650390987991 is an apocalyptic number.

650390987991 is a deficient number, since it is larger than the sum of its proper divisors (216796996001).

650390987991 is a wasteful number, since it uses less digits than its factorization.

650390987991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216796996000.

The product of its (nonzero) digits is 33067440, while the sum is 66.

The spelling of 650390987991 in words is "six hundred fifty billion, three hundred ninety million, nine hundred eighty-seven thousand, nine hundred ninety-one".