645908809546 has 64 divisors (see below), whose sum is σ = 1301224974336. Its totient is φ = 232228152000.

The previous prime is 645908809517. The next prime is 645908809571.

645908809546 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×645908809546² (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 31 ways as a sum of consecutive naturals, for example, 7208721 + ... + 7297771.

It is an arithmetic number, because the mean of its divisors is an integer number (20331640224).

Almost surely, 2^645908809546 is an apocalyptic number.

645908809546 is an abundant number, since it is smaller than the sum of its proper divisors (655316164790).

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

645908809546 is a wasteful number, since it uses less digits than its factorization.

645908809546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92707.

The product of its (nonzero) digits is 74649600, while the sum is 64.

The spelling of 645908809546 in words is "six hundred forty-five billion, nine hundred eight million, eight hundred nine thousand, five hundred forty-six".