64638505 has 8 divisors (see below), whose sum is σ = 82129032. Its totient is φ = 48668928.

The previous prime is 64638493. The next prime is 64638523. The reversal of 64638505 is 50583646.

It can be written as a sum of positive squares in 4 ways, for example, as 18344089 + 46294416 = 4283^2 + 6804^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 64638505 - 2⁵ = 64638473 is a prime.

It is a Duffinian 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, 380142 + ... + 380311.

It is an arithmetic number, because the mean of its divisors is an integer number (10266129).

Almost surely, 2^64638505 is an apocalyptic number.

It is an amenable number.

64638505 is a deficient number, since it is larger than the sum of its proper divisors (17490527).

64638505 is a wasteful number, since it uses less digits than its factorization.

64638505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 760475.

The product of its (nonzero) digits is 86400, while the sum is 37.

The square root of 64638505 is about 8039.8075225717. The cubic root of 64638505 is about 401.3258194020.

The spelling of 64638505 in words is "sixty-four million, six hundred thirty-eight thousand, five hundred five".