645750785 has 8 divisors (see below), whose sum is σ = 775053096. Its totient is φ = 516499200.

The previous prime is 645750769. The next prime is 645750827. The reversal of 645750785 is 587057546.

It can be written as a sum of positive squares in 4 ways, for example, as 83302129 + 562448656 = 9127^2 + 23716^2 .

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

It is not a de Polignac number, because 645750785 - 2⁴ = 645750769 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, 26135 + ... + 44435.

It is an arithmetic number, because the mean of its divisors is an integer number (96881637).

Almost surely, 2^645750785 is an apocalyptic number.

It is an amenable number.

645750785 is a deficient number, since it is larger than the sum of its proper divisors (129302311).

645750785 is a wasteful number, since it uses less digits than its factorization.

645750785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25363.

The product of its (nonzero) digits is 1176000, while the sum is 47.

The square root of 645750785 is about 25411.6269648364. The cubic root of 645750785 is about 864.3473687710.

The spelling of 645750785 in words is "six hundred forty-five million, seven hundred fifty thousand, seven hundred eighty-five".