645635242457 has 2 divisors, whose sum is σ = 645635242458. Its totient is φ = 645635242456.

The previous prime is 645635242453. The next prime is 645635242481. The reversal of 645635242457 is 754242536546.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 640161610201 + 5473632256 = 800101^2 + 73984^2 .

It is a cyclic number.

It is not a de Polignac number, because 645635242457 - 2² = 645635242453 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 645635242399 and 645635242408.

It is not a weakly prime, because it can be changed into another prime (645635242451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322817621228 + 322817621229.

It is an arithmetic number, because the mean of its divisors is an integer number (322817621229).

Almost surely, 2^645635242457 is an apocalyptic number.

It is an amenable number.

645635242457 is a deficient number, since it is larger than the sum of its proper divisors (1).

645635242457 is an equidigital number, since it uses as much as digits as its factorization.

645635242457 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24192000, while the sum is 53.

The spelling of 645635242457 in words is "six hundred forty-five billion, six hundred thirty-five million, two hundred forty-two thousand, four hundred fifty-seven".