645776855 has 8 divisors (see below), whose sum is σ = 793833264. Its totient is φ = 504020800.

The previous prime is 645776837. The next prime is 645776863. The reversal of 645776855 is 558677546.

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

It is not a de Polignac number, because 645776855 - 2²² = 641582551 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 645776797 and 645776806.

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 7 ways as a sum of consecutive naturals, for example, 1574861 + ... + 1575270.

It is an arithmetic number, because the mean of its divisors is an integer number (99229158).

Almost surely, 2^645776855 is an apocalyptic number.

645776855 is a deficient number, since it is larger than the sum of its proper divisors (148056409).

645776855 is a wasteful number, since it uses less digits than its factorization.

645776855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3150177.

The product of its digits is 7056000, while the sum is 53.

The square root of 645776855 is about 25412.1399138286. The cubic root of 645776855 is about 864.3590003133.

The spelling of 645776855 in words is "six hundred forty-five million, seven hundred seventy-six thousand, eight hundred fifty-five".