645818185078 has 16 divisors (see below), whose sum is σ = 1068667480080. Its totient is φ = 290255363200.

The previous prime is 645818185031. The next prime is 645818185169. The reversal of 645818185078 is 870581818546.

It is a happy number.

It is a super-2 number, since 2×645818185078² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 164915863 + ... + 164919778.

It is an arithmetic number, because the mean of its divisors is an integer number (66791717505).

Almost surely, 2^645818185078 is an apocalyptic number.

645818185078 is a deficient number, since it is larger than the sum of its proper divisors (422849295002).

645818185078 is a wasteful number, since it uses less digits than its factorization.

645818185078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 329835743.

The product of its (nonzero) digits is 17203200, while the sum is 61.

The spelling of 645818185078 in words is "six hundred forty-five billion, eight hundred eighteen million, one hundred eighty-five thousand, seventy-eight".