1365725643521 has 2 divisors, whose sum is σ = 1365725643522. Its totient is φ = 1365725643520.

The previous prime is 1365725643439. The next prime is 1365725643533. The reversal of 1365725643521 is 1253465275631.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1361039556496 + 4686087025 = 1166636^2 + 68455^2 .

It is a cyclic number.

It is not a de Polignac number, because 1365725643521 - 2³⁴ = 1348545774337 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1365725643521.

It is not a weakly prime, because it can be changed into another prime (1365725642521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 682862821760 + 682862821761.

It is an arithmetic number, because the mean of its divisors is an integer number (682862821761).

Almost surely, 2^{1365725643521} is an apocalyptic number.

It is an amenable number.

1365725643521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1365725643521 is an equidigital number, since it uses as much as digits as its factorization.

1365725643521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4536000, while the sum is 50.

The spelling of 1365725643521 in words is "one trillion, three hundred sixty-five billion, seven hundred twenty-five million, six hundred forty-three thousand, five hundred twenty-one".