645371438857 has 4 divisors (see below), whose sum is σ = 645694288000. Its totient is φ = 645048589716.

The previous prime is 645371438819. The next prime is 645371438893. The reversal of 645371438857 is 758834173546.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 645371438857 - 2²³ = 645363050249 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 645371438795 and 645371438804.

It is not an unprimeable number, because it can be changed into a prime (645371438807) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 161421573 + ... + 161425570.

It is an arithmetic number, because the mean of its divisors is an integer number (161423572000).

Almost surely, 2^645371438857 is an apocalyptic number.

It is an amenable number.

645371438857 is a deficient number, since it is larger than the sum of its proper divisors (322849143).

645371438857 is a wasteful number, since it uses less digits than its factorization.

645371438857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322849142.

The product of its digits is 67737600, while the sum is 61.

The spelling of 645371438857 in words is "six hundred forty-five billion, three hundred seventy-one million, four hundred thirty-eight thousand, eight hundred fifty-seven".