64917760 has 72 divisors (see below), whose sum is σ = 159419736. Its totient is φ = 25313280.

The previous prime is 64917733. The next prime is 64917803. The reversal of 64917760 is 6771946.

It can be written as a sum of positive squares in 4 ways, for example, as 1937664 + 62980096 = 1392^2 + 7936^2 .

It is a Harshad number since it is a multiple of its sum of digits (40).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 51862 + ... + 53098.

It is an arithmetic number, because the mean of its divisors is an integer number (2214163).

Almost surely, 2^64917760 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 64917760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79709868).

64917760 is an abundant number, since it is smaller than the sum of its proper divisors (94501976).

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

64917760 is a wasteful number, since it uses less digits than its factorization.

64917760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1299 (or 1285 counting only the distinct ones).

The product of its (nonzero) digits is 63504, while the sum is 40.

The square root of 64917760 is about 8057.1558257241. The cubic root of 64917760 is about 401.9029327614.

The spelling of 64917760 in words is "sixty-four million, nine hundred seventeen thousand, seven hundred sixty".