64777728 has 80 divisors (see below), whose sum is σ = 174270096. Its totient is φ = 21381120.

The previous prime is 64777711. The next prime is 64777751. The reversal of 64777728 is 82777746.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 277900 + ... + 278132.

Almost surely, 2^64777728 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 64777728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (87135048).

64777728 is an abundant number, since it is smaller than the sum of its proper divisors (109492368).

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

64777728 is a wasteful number, since it uses less digits than its factorization.

64777728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 435 (or 419 counting only the distinct ones).

The product of its digits is 921984, while the sum is 48.

The square root of 64777728 is about 8048.4612193885. The cubic root of 64777728 is about 401.6137474593.

The spelling of 64777728 in words is "sixty-four million, seven hundred seventy-seven thousand, seven hundred twenty-eight".