65820645561 has 32 divisors (see below), whose sum is σ = 98910167040. Its totient is φ = 38572185600.

The previous prime is 65820645533. The next prime is 65820645563. The reversal of 65820645561 is 16554602856.

It is not a de Polignac number, because 65820645561 - 2⁵ = 65820645529 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 65820645561.

It is not an unprimeable number, because it can be changed into a prime (65820645563) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1224825 + ... + 1277433.

It is an arithmetic number, because the mean of its divisors is an integer number (3090942720).

Almost surely, 2^65820645561 is an apocalyptic number.

It is an amenable number.

65820645561 is a deficient number, since it is larger than the sum of its proper divisors (33089521479).

65820645561 is a wasteful number, since it uses less digits than its factorization.

65820645561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53877.

The product of its (nonzero) digits is 1728000, while the sum is 48.

The spelling of 65820645561 in words is "sixty-five billion, eight hundred twenty million, six hundred forty-five thousand, five hundred sixty-one".