645707507645 has 16 divisors (see below), whose sum is σ = 786843072000. Its totient is φ = 508606395648.

The previous prime is 645707507611. The next prime is 645707507713. The reversal of 645707507645 is 546705707546.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 645707507645 - 2¹⁶ = 645707442109 is a prime.

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 15 ways as a sum of consecutive naturals, for example, 2134940 + ... + 2418549.

It is an arithmetic number, because the mean of its divisors is an integer number (49177692000).

Almost surely, 2^645707507645 is an apocalyptic number.

It is an amenable number.

645707507645 is a deficient number, since it is larger than the sum of its proper divisors (141135564355).

645707507645 is a wasteful number, since it uses less digits than its factorization.

645707507645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4553932.

The product of its (nonzero) digits is 24696000, while the sum is 56.

The spelling of 645707507645 in words is "six hundred forty-five billion, seven hundred seven million, five hundred seven thousand, six hundred forty-five".