645816654133 has 24 divisors (see below), whose sum is σ = 798543035352. Its totient is φ = 518967558144.

The previous prime is 645816654127. The next prime is 645816654137. The reversal of 645816654133 is 331456618546.

645816654133 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 319539217284 + 326277436849 = 565278^2 + 571207^2 .

It is not a de Polignac number, because 645816654133 - 2⁹ = 645816653621 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645816654137) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1294266 + ... + 1722427.

It is an arithmetic number, because the mean of its divisors is an integer number (33272626473).

Almost surely, 2^645816654133 is an apocalyptic number.

It is an amenable number.

645816654133 is a deficient number, since it is larger than the sum of its proper divisors (152726381219).

645816654133 is a wasteful number, since it uses less digits than its factorization.

645816654133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3016981 (or 3016974 counting only the distinct ones).

The product of its digits is 6220800, while the sum is 52.

The spelling of 645816654133 in words is "six hundred forty-five billion, eight hundred sixteen million, six hundred fifty-four thousand, one hundred thirty-three".