645165561546 has 32 divisors (see below), whose sum is σ = 1564037726400. Its totient is φ = 195504715440.

The previous prime is 645165561461. The next prime is 645165561571.

645165561546 is a `hidden beast` number, since 6 + 4 + 5 + 16 + 5 + 5 + 615 + 4 + 6 = 666.

645165561546 is nontrivially palindromic in base 10.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 645165561492 and 645165561501.

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, 543068061 + ... + 543069248.

It is an arithmetic number, because the mean of its divisors is an integer number (48876178950).

Almost surely, 2^645165561546 is an apocalyptic number.

645165561546 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

645165561546 is an abundant number, since it is smaller than the sum of its proper divisors (918872164854).

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

645165561546 is a wasteful number, since it uses less digits than its factorization.

645165561546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1086137331 (or 1086137325 counting only the distinct ones).

The product of its digits is 12960000, while the sum is 54.

The spelling of 645165561546 in words is "six hundred forty-five billion, one hundred sixty-five million, five hundred sixty-one thousand, five hundred forty-six".