645647746546 has 32 divisors (see below), whose sum is σ = 1071635158080. Its totient is φ = 289301448000.

The previous prime is 645647746501. The next prime is 645647746561.

It is a happy number.

645647746546 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×645647746546² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 125596 + ... + 1143271.

It is an arithmetic number, because the mean of its divisors is an integer number (33488598690).

Almost surely, 2^645647746546 is an apocalyptic number.

645647746546 is a deficient number, since it is larger than the sum of its proper divisors (425987411534).

645647746546 is a wasteful number, since it uses less digits than its factorization.

645647746546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1269210.

The product of its digits is 406425600, while the sum is 64.

The spelling of 645647746546 in words is "six hundred forty-five billion, six hundred forty-seven million, seven hundred forty-six thousand, five hundred forty-six".