85206720645 has 24 divisors (see below), whose sum is σ = 149125556736. Its totient is φ = 45002382048.

The previous prime is 85206720637. The next prime is 85206720719. The reversal of 85206720645 is 54602760258.

85206720645 is a `hidden beast` number, since 8 + 520 + 67 + 2 + 0 + 64 + 5 = 666.

It is not a de Polignac number, because 85206720645 - 2³ = 85206720637 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 85206720645.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9187029 + ... + 9196298.

It is an arithmetic number, because the mean of its divisors is an integer number (6213564864).

Almost surely, 2^85206720645 is an apocalyptic number.

It is an amenable number.

85206720645 is a deficient number, since it is larger than the sum of its proper divisors (63918836091).

85206720645 is a wasteful number, since it uses less digits than its factorization.

85206720645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18383441 (or 18383438 counting only the distinct ones).

The product of its (nonzero) digits is 806400, while the sum is 45.

The spelling of 85206720645 in words is "eighty-five billion, two hundred six million, seven hundred twenty thousand, six hundred forty-five".