64817280 has 384 divisors, whose sum is σ = 260467200. Its totient is φ = 15206400.

The previous prime is 64817231. The next prime is 64817309. The reversal of 64817280 is 8271846.

64817280 is a `hidden beast` number, since 648 + 1 + 7 + 2 + 8 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

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

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2090865 + ... + 2090895.

It is an arithmetic number, because the mean of its divisors is an integer number (678300).

Almost surely, 2^64817280 is an apocalyptic number.

64817280 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 64817280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (130233600).

64817280 is an abundant number, since it is smaller than the sum of its proper divisors (195649920).

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

64817280 is a wasteful number, since it uses less digits than its factorization.

64817280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81 (or 52 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 64817280 is about 8050.9179600838. The cubic root of 64817280 is about 401.6954699668.

The spelling of 64817280 in words is "sixty-four million, eight hundred seventeen thousand, two hundred eighty".