648918789 has 4 divisors (see below), whose sum is σ = 865225056. Its totient is φ = 432612524.

The previous prime is 648918779. The next prime is 648918821. The reversal of 648918789 is 987819846.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 648918789 - 2⁴ = 648918773 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (648918749) 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, 108153129 + ... + 108153134.

It is an arithmetic number, because the mean of its divisors is an integer number (216306264).

Almost surely, 2^648918789 is an apocalyptic number.

It is an amenable number.

648918789 is a deficient number, since it is larger than the sum of its proper divisors (216306267).

648918789 is a wasteful number, since it uses less digits than its factorization.

648918789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216306266.

The product of its digits is 6967296, while the sum is 60.

The square root of 648918789 is about 25473.8844505505. The cubic root of 648918789 is about 865.7585376298.

The spelling of 648918789 in words is "six hundred forty-eight million, nine hundred eighteen thousand, seven hundred eighty-nine".