645666666546 has 32 divisors (see below), whose sum is σ = 1482870816000. Its totient is φ = 185358851280.

The previous prime is 645666666517. The next prime is 645666666551.

645666666546 is nontrivially palindromic in base 10.

645666666546 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (66).

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, 257441596 + ... + 257444103.

It is an arithmetic number, because the mean of its divisors is an integer number (46339713000).

Almost surely, 2^645666666546 is an apocalyptic number.

645666666546 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

645666666546 is an abundant number, since it is smaller than the sum of its proper divisors (837204149454).

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

645666666546 is a wasteful number, since it uses less digits than its factorization.

645666666546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 514885734.

The product of its digits is 671846400, while the sum is 66.

The spelling of 645666666546 in words is "six hundred forty-five billion, six hundred sixty-six million, six hundred sixty-six thousand, five hundred forty-six".