1565643061 has 2 divisors, whose sum is σ = 1565643062. Its totient is φ = 1565643060.

The previous prime is 1565643059. The next prime is 1565643091. The reversal of 1565643061 is 1603465651.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1494982225 + 70660836 = 38665^2 + 8406^2 .

It is a cyclic number.

It is not a de Polignac number, because 1565643061 - 2¹ = 1565643059 is a prime.

Together with 1565643059, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 1565643061.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1565643091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 782821530 + 782821531.

It is an arithmetic number, because the mean of its divisors is an integer number (782821531).

Almost surely, 2^1565643061 is an apocalyptic number.

It is an amenable number.

1565643061 is a deficient number, since it is larger than the sum of its proper divisors (1).

1565643061 is an equidigital number, since it uses as much as digits as its factorization.

1565643061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64800, while the sum is 37.

The square root of 1565643061 is about 39568.2077051766. The cubic root of 1565643061 is about 1161.1747564396.

The spelling of 1565643061 in words is "one billion, five hundred sixty-five million, six hundred forty-three thousand, sixty-one".