1356245205661 has 2 divisors, whose sum is σ = 1356245205662. Its totient is φ = 1356245205660.

The previous prime is 1356245205613. The next prime is 1356245205677. The reversal of 1356245205661 is 1665025426531.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1047898221561 + 308346984100 = 1023669^2 + 555290^2 .

It is an emirp because it is prime and its reverse (1665025426531) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1356245205661 - 2¹⁷ = 1356245074589 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1356245205961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 678122602830 + 678122602831.

It is an arithmetic number, because the mean of its divisors is an integer number (678122602831).

Almost surely, 2^{1356245205661} is an apocalyptic number.

It is an amenable number.

1356245205661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1356245205661 is an equidigital number, since it uses as much as digits as its factorization.

1356245205661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296000, while the sum is 46.

The spelling of 1356245205661 in words is "one trillion, three hundred fifty-six billion, two hundred forty-five million, two hundred five thousand, six hundred sixty-one".