1564433512661 has 2 divisors, whose sum is σ = 1564433512662. Its totient is φ = 1564433512660.

The previous prime is 1564433512633. The next prime is 1564433512753. The reversal of 1564433512661 is 1662153344651.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 987698068900 + 576735443761 = 993830^2 + 759431^2 .

It is an emirp because it is prime and its reverse (1662153344651) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1564433512661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1564433512561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 782216756330 + 782216756331.

It is an arithmetic number, because the mean of its divisors is an integer number (782216756331).

Almost surely, 2^{1564433512661} is an apocalyptic number.

It is an amenable number.

1564433512661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1564433512661 is an equidigital number, since it uses as much as digits as its factorization.

1564433512661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1555200, while the sum is 47.

The spelling of 1564433512661 in words is "one trillion, five hundred sixty-four billion, four hundred thirty-three million, five hundred twelve thousand, six hundred sixty-one".