648521280 has 252 divisors, whose sum is σ = 2453181276. Its totient is φ = 157132800.

The previous prime is 648521239. The next prime is 648521297. The reversal of 648521280 is 82125846.

648521280 is a `hidden beast` number, since 648 + 5 + 2 + 1 + 2 + 8 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 71368704 + 577152576 = 8448^2 + 24024^2 .

It is a super-2 number, since 2×648521280² = 841159701225676800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 347550 + ... + 349410.

Almost surely, 2^648521280 is an apocalyptic number.

648521280 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 648521280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1226590638).

648521280 is an abundant number, since it is smaller than the sum of its proper divisors (1804659996).

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

648521280 is a wasteful number, since it uses less digits than its factorization.

648521280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1906 (or 1882 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 36.

The square root of 648521280 is about 25466.0809705773. The cubic root of 648521280 is about 865.5817219215.

The spelling of 648521280 in words is "six hundred forty-eight million, five hundred twenty-one thousand, two hundred eighty".