645075447775 has 72 divisors (see below), whose sum is σ = 935972129664. Its totient is φ = 437256537600.

The previous prime is 645075447749. The next prime is 645075447827. The reversal of 645075447775 is 577744570546.

It is not a de Polignac number, because 645075447775 - 2³¹ = 642927964127 is a prime.

It is a super-2 number, since 2×645075447775² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 8146524 + ... + 8225326.

It is an arithmetic number, because the mean of its divisors is an integer number (12999612912).

Almost surely, 2^645075447775 is an apocalyptic number.

645075447775 is a deficient number, since it is larger than the sum of its proper divisors (290896681889).

645075447775 is a wasteful number, since it uses less digits than its factorization.

645075447775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78961 (or 78939 counting only the distinct ones).

The product of its (nonzero) digits is 115248000, while the sum is 61.

The spelling of 645075447775 in words is "six hundred forty-five billion, seventy-five million, four hundred forty-seven thousand, seven hundred seventy-five".