1640564543 has 2 divisors, whose sum is σ = 1640564544. Its totient is φ = 1640564542.

The previous prime is 1640564489. The next prime is 1640564567. The reversal of 1640564543 is 3454650461.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1640564543 - 2⁸ = 1640564287 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 1640564497 and 1640564506.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1640564573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820282271 + 820282272.

It is an arithmetic number, because the mean of its divisors is an integer number (820282272).

Almost surely, 2^1640564543 is an apocalyptic number.

1640564543 is a deficient number, since it is larger than the sum of its proper divisors (1).

1640564543 is an equidigital number, since it uses as much as digits as its factorization.

1640564543 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 172800, while the sum is 38.

The square root of 1640564543 is about 40503.8830607634. The cubic root of 1640564543 is about 1179.4090076567.

The spelling of 1640564543 in words is "one billion, six hundred forty million, five hundred sixty-four thousand, five hundred forty-three".