1605552643 has 2 divisors, whose sum is σ = 1605552644. Its totient is φ = 1605552642.

The previous prime is 1605552569. The next prime is 1605552653. The reversal of 1605552643 is 3462555061.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1605552643 is a prime.

It is not a weakly prime, because it can be changed into another prime (1605552653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 802776321 + 802776322.

It is an arithmetic number, because the mean of its divisors is an integer number (802776322).

Almost surely, 2^1605552643 is an apocalyptic number.

1605552643 is a deficient number, since it is larger than the sum of its proper divisors (1).

1605552643 is an equidigital number, since it uses as much as digits as its factorization.

1605552643 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108000, while the sum is 37.

The square root of 1605552643 is about 40069.3479233191. The cubic root of 1605552643 is about 1170.9585353608.

The spelling of 1605552643 in words is "one billion, six hundred five million, five hundred fifty-two thousand, six hundred forty-three".