645415051553 has 2 divisors, whose sum is σ = 645415051554. Its totient is φ = 645415051552.

The previous prime is 645415051537. The next prime is 645415051639. The reversal of 645415051553 is 355150514546.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 627029589904 + 18385461649 = 791852^2 + 135593^2 .

It is a cyclic number.

It is not a de Polignac number, because 645415051553 - 2⁴ = 645415051537 is a prime.

It is a super-3 number, since 3×645415051553³ (a number of 36 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (645415051513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322707525776 + 322707525777.

It is an arithmetic number, because the mean of its divisors is an integer number (322707525777).

Almost surely, 2^645415051553 is an apocalyptic number.

It is an amenable number.

645415051553 is a deficient number, since it is larger than the sum of its proper divisors (1).

645415051553 is an equidigital number, since it uses as much as digits as its factorization.

645415051553 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 900000, while the sum is 44.

The spelling of 645415051553 in words is "six hundred forty-five billion, four hundred fifteen million, fifty-one thousand, five hundred fifty-three".