6436820465 has 4 divisors (see below), whose sum is σ = 7724184564. Its totient is φ = 5149456368.

The previous prime is 6436820443. The next prime is 6436820471. The reversal of 6436820465 is 5640286346.

6436820465 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5640286346 = 2 ⋅2820143173.

It can be written as a sum of positive squares in 2 ways, for example, as 1296504049 + 5140316416 = 36007^2 + 71696^2 .

It is a cyclic number.

It is not a de Polignac number, because 6436820465 - 2³⁰ = 5363078641 is a prime.

It is a Duffinian 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, 643682042 + ... + 643682051.

It is an arithmetic number, because the mean of its divisors is an integer number (1931046141).

Almost surely, 2^6436820465 is an apocalyptic number.

It is an amenable number.

6436820465 is a deficient number, since it is larger than the sum of its proper divisors (1287364099).

6436820465 is a wasteful number, since it uses less digits than its factorization.

6436820465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1287364098.

The product of its (nonzero) digits is 829440, while the sum is 44.

The square root of 6436820465 is about 80229.7978621410. The cubic root of 6436820465 is about 1860.1892574408.

The spelling of 6436820465 in words is "six billion, four hundred thirty-six million, eight hundred twenty thousand, four hundred sixty-five".