645557046 has 8 divisors (see below), whose sum is σ = 1291114104. Its totient is φ = 215185680.

The previous prime is 645557041. The next prime is 645557089. The reversal of 645557046 is 640755546.

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

645557046 is an admirable number.

It is a super-2 number, since 2×645557046² = 833487799280492232, which contains 22 as substring.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 645556989 and 645557007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645557041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53796415 + ... + 53796426.

It is an arithmetic number, because the mean of its divisors is an integer number (161389263).

Almost surely, 2^645557046 is an apocalyptic number.

645557046 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

645557046 is a wasteful number, since it uses less digits than its factorization.

645557046 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107592846.

The product of its (nonzero) digits is 504000, while the sum is 42.

The square root of 645557046 is about 25407.8146639966. The cubic root of 645557046 is about 864.2609192467.

The spelling of 645557046 in words is "six hundred forty-five million, five hundred fifty-seven thousand, forty-six".