6398720064 has 315 divisors, whose sum is σ = 21057384733. Its totient is φ = 1919808000.

The previous prime is 6398720057. The next prime is 6398720071. The reversal of 6398720064 is 4600278936.

The square root of 6398720064 is 79992.

It is a perfect power (a square), and thus also a powerful number.

6398720064 is a `hidden beast` number, since 639 + 8 + 7 + 2 + 0 + 0 + 6 + 4 = 666.

It is an interprime number because it is at equal distance from previous prime (6398720057) and next prime (6398720071).

It can be written as a sum of positive squares in only one way, i.e., 6147814464 + 250905600 = 78408^2 + 15840^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 63353614 + ... + 63353714.

Almost surely, 2^6398720064 is an apocalyptic number.

6398720064 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

6398720064 is the 79992-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6398720064

6398720064 is an abundant number, since it is smaller than the sum of its proper divisors (14658664669).

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

6398720064 is a wasteful number, since it uses less digits than its factorization.

6398720064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 248 (or 117 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 45.

The cubic root of 6398720064 is about 1856.5117556799.

The spelling of 6398720064 in words is "six billion, three hundred ninety-eight million, seven hundred twenty thousand, sixty-four".