645276563 has 16 divisors (see below), whose sum is σ = 676915200. Its totient is φ = 614399040.

The previous prime is 645276547. The next prime is 645276571. The reversal of 645276563 is 365672546.

It is a happy number.

645276563 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 645276563 - 2⁴ = 645276547 is a prime.

It is a super-3 number, since 3×645276563³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645279563) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 570983 + ... + 572111.

It is an arithmetic number, because the mean of its divisors is an integer number (42307200).

Almost surely, 2^645276563 is an apocalyptic number.

645276563 is a deficient number, since it is larger than the sum of its proper divisors (31638637).

645276563 is a wasteful number, since it uses less digits than its factorization.

645276563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1442.

The product of its digits is 907200, while the sum is 44.

The square root of 645276563 is about 25402.2944436128. The cubic root of 645276563 is about 864.1357324729.

The spelling of 645276563 in words is "six hundred forty-five million, two hundred seventy-six thousand, five hundred sixty-three".