64778560 has 168 divisors, whose sum is σ = 194584320. Its totient is φ = 20106240.

The previous prime is 64778513. The next prime is 64778563. The reversal of 64778560 is 6587746.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64778563) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 270921 + ... + 271159.

It is an arithmetic number, because the mean of its divisors is an integer number (1158240).

Almost surely, 2^64778560 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64778560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (97292160).

64778560 is an abundant number, since it is smaller than the sum of its proper divisors (129805760).

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

64778560 is a wasteful number, since it uses less digits than its factorization.

64778560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285 (or 264 counting only the distinct ones).

The product of its (nonzero) digits is 282240, while the sum is 43.

The square root of 64778560 is about 8048.5129061212. The cubic root of 64778560 is about 401.6154668837.

The spelling of 64778560 in words is "sixty-four million, seven hundred seventy-eight thousand, five hundred sixty".