645998054 has 16 divisors (see below), whose sum is σ = 1059113328. Its totient is φ = 293702112.

The previous prime is 645998053. The next prime is 645998063. The reversal of 645998054 is 450899546.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 645997993 and 645998011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645998051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 183677 + ... + 187160.

It is an arithmetic number, because the mean of its divisors is an integer number (66194583).

Almost surely, 2^645998054 is an apocalyptic number.

645998054 is a deficient number, since it is larger than the sum of its proper divisors (413115274).

645998054 is a wasteful number, since it uses less digits than its factorization.

645998054 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 370919.

The product of its (nonzero) digits is 1555200, while the sum is 50.

The square root of 645998054 is about 25416.4917720759. The cubic root of 645998054 is about 864.4576791469.

The spelling of 645998054 in words is "six hundred forty-five million, nine hundred ninety-eight thousand, fifty-four".