645387783571 has 2 divisors, whose sum is σ = 645387783572. Its totient is φ = 645387783570.

The previous prime is 645387783541. The next prime is 645387783583. The reversal of 645387783571 is 175387783546.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 645387783571 - 2¹⁵ = 645387750803 is a prime.

It is not a weakly prime, because it can be changed into another prime (645387783541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322693891785 + 322693891786.

It is an arithmetic number, because the mean of its divisors is an integer number (322693891786).

Almost surely, 2^645387783571 is an apocalyptic number.

645387783571 is a deficient number, since it is larger than the sum of its proper divisors (1).

645387783571 is an equidigital number, since it uses as much as digits as its factorization.

645387783571 is an evil number, because the sum of its binary digits is even.

The product of its digits is 118540800, while the sum is 64.

The spelling of 645387783571 in words is "six hundred forty-five billion, three hundred eighty-seven million, seven hundred eighty-three thousand, five hundred seventy-one".