64820005 has 4 divisors (see below), whose sum is σ = 77784012. Its totient is φ = 51856000.

The previous prime is 64819999. The next prime is 64820023. The reversal of 64820005 is 50002846.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 38266596 + 26553409 = 6186^2 + 5153^2 .

It is not a de Polignac number, because 64820005 - 2⁹ = 64819493 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6481996 + ... + 6482005.

It is an arithmetic number, because the mean of its divisors is an integer number (19446003).

Almost surely, 2^64820005 is an apocalyptic number.

It is an amenable number.

64820005 is a deficient number, since it is larger than the sum of its proper divisors (12964007).

64820005 is a wasteful number, since it uses less digits than its factorization.

64820005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12964006.

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 64820005 is about 8051.0871936652. The cubic root of 64820005 is about 401.7010991489.

The spelling of 64820005 in words is "sixty-four million, eight hundred twenty thousand, five".