648874517491 has 4 divisors (see below), whose sum is σ = 655174270192. Its totient is φ = 642574764792.

The previous prime is 648874517483. The next prime is 648874517503. The reversal of 648874517491 is 194715478846.

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

It is a cyclic number.

It is not a de Polignac number, because 648874517491 - 2³ = 648874517483 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (648874517441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3149876196 + ... + 3149876401.

It is an arithmetic number, because the mean of its divisors is an integer number (163793567548).

Almost surely, 2^648874517491 is an apocalyptic number.

648874517491 is a deficient number, since it is larger than the sum of its proper divisors (6299752701).

648874517491 is a wasteful number, since it uses less digits than its factorization.

648874517491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6299752700.

The product of its digits is 54190080, while the sum is 64.

The spelling of 648874517491 in words is "six hundred forty-eight billion, eight hundred seventy-four million, five hundred seventeen thousand, four hundred ninety-one".