649185710891 has 8 divisors (see below), whose sum is σ = 650488212000. Its totient is φ = 647884077120.

The previous prime is 649185710881. The next prime is 649185710951. The reversal of 649185710891 is 198017581946.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-649185710891 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 649185710891.

It is not an unprimeable number, because it can be changed into a prime (649185710881) 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 7 ways as a sum of consecutive naturals, for example, 1292135 + ... + 1722783.

It is an arithmetic number, because the mean of its divisors is an integer number (81311026500).

Almost surely, 2^649185710891 is an apocalyptic number.

649185710891 is a deficient number, since it is larger than the sum of its proper divisors (1302501109).

649185710891 is a wasteful number, since it uses less digits than its factorization.

649185710891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 433669.

The product of its (nonzero) digits is 4354560, while the sum is 59.

The spelling of 649185710891 in words is "six hundred forty-nine billion, one hundred eighty-five million, seven hundred ten thousand, eight hundred ninety-one".