648778988 has 48 divisors (see below), whose sum is σ = 1337681184. Its totient is φ = 271434240.

The previous prime is 648778987. The next prime is 648778993. The reversal of 648778988 is 889877846.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (648778987) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 225656 + ... + 228512.

It is an arithmetic number, because the mean of its divisors is an integer number (27868358).

Almost surely, 2^648778988 is an apocalyptic number.

It is an amenable number.

648778988 is an abundant number, since it is smaller than the sum of its proper divisors (688902196).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

648778988 is a wasteful number, since it uses less digits than its factorization.

648778988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3282 (or 3280 counting only the distinct ones).

The product of its digits is 43352064, while the sum is 65.

The square root of 648778988 is about 25471.1402964218. The cubic root of 648778988 is about 865.6963610760.

The spelling of 648778988 in words is "six hundred forty-eight million, seven hundred seventy-eight thousand, nine hundred eighty-eight".