64478880 has 72 divisors (see below), whose sum is σ = 220039092. Its totient is φ = 17193984.

The previous prime is 64478851. The next prime is 64478881. The reversal of 64478880 is 8887446.

It can be written as a sum of positive squares in 2 ways, for example, as 60652944 + 3825936 = 7788^2 + 1956^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (64478881) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20949 + ... + 23828.

Almost surely, 2^64478880 is an apocalyptic number.

64478880 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

64478880 is an abundant number, since it is smaller than the sum of its proper divisors (155560212).

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

64478880 is a wasteful number, since it uses less digits than its factorization.

64478880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44798 (or 44787 counting only the distinct ones).

The product of its (nonzero) digits is 344064, while the sum is 45.

The square root of 64478880 is about 8029.8742206837. The cubic root of 64478880 is about 400.9951886123.

It can be divided in two parts, 644 and 78880, that added together give a square (79524 = 282²).

The spelling of 64478880 in words is "sixty-four million, four hundred seventy-eight thousand, eight hundred eighty".