648319816 has 8 divisors (see below), whose sum is σ = 1215599670. Its totient is φ = 324159904.

The previous prime is 648319807. The next prime is 648319817. The reversal of 648319816 is 618913846.

It can be written as a sum of positive squares in only one way, i.e., 549714916 + 98604900 = 23446^2 + 9930^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (46) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (648319817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40519981 + ... + 40519996.

Almost surely, 2^648319816 is an apocalyptic number.

It is an amenable number.

648319816 is a deficient number, since it is larger than the sum of its proper divisors (567279854).

648319816 is a wasteful number, since it uses less digits than its factorization.

648319816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81039983 (or 81039979 counting only the distinct ones).

The product of its digits is 248832, while the sum is 46.

The square root of 648319816 is about 25462.1251273337. The cubic root of 648319816 is about 865.4920812667.

It can be divided in two parts, 64831 and 9816, that added together give a palindrome (74647).

The spelling of 648319816 in words is "six hundred forty-eight million, three hundred nineteen thousand, eight hundred sixteen".