645440166428 has 12 divisors (see below), whose sum is σ = 1129800806232. Its totient is φ = 322639936080.

The previous prime is 645440166419. The next prime is 645440166433. The reversal of 645440166428 is 824661044546.

645440166428 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20018663 + ... + 20050878.

It is an arithmetic number, because the mean of its divisors is an integer number (94150067186).

Almost surely, 2^645440166428 is an apocalyptic number.

It is an amenable number.

645440166428 is a deficient number, since it is larger than the sum of its proper divisors (484360639804).

645440166428 is a wasteful number, since it uses less digits than its factorization.

645440166428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40073572 (or 40073570 counting only the distinct ones).

The product of its (nonzero) digits is 4423680, while the sum is 50.

The spelling of 645440166428 in words is "six hundred forty-five billion, four hundred forty million, one hundred sixty-six thousand, four hundred twenty-eight".