1564550663381 has 2 divisors, whose sum is σ = 1564550663382. Its totient is φ = 1564550663380.

The previous prime is 1564550663363. The next prime is 1564550663441. The reversal of 1564550663381 is 1833660554651.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 856487317156 + 708063346225 = 925466^2 + 841465^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1564550663381 is a prime.

It is a super-2 number, since 2×1564550663381² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1564550663341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 782275331690 + 782275331691.

It is an arithmetic number, because the mean of its divisors is an integer number (782275331691).

Almost surely, 2^{1564550663381} is an apocalyptic number.

It is an amenable number.

1564550663381 is a deficient number, since it is larger than the sum of its proper divisors (1).

1564550663381 is an equidigital number, since it uses as much as digits as its factorization.

1564550663381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776000, while the sum is 53.

The spelling of 1564550663381 in words is "one trillion, five hundred sixty-four billion, five hundred fifty million, six hundred sixty-three thousand, three hundred eighty-one".