25603838543561 has 2 divisors, whose sum is σ = 25603838543562. Its totient is φ = 25603838543560.

The previous prime is 25603838543537. The next prime is 25603838543567. The reversal of 25603838543561 is 16534583830652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22786006293961 + 2817832249600 = 4773469^2 + 1678640^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25603838543561 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 25603838543561.

It is not a weakly prime, because it can be changed into another prime (25603838543567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12801919271780 + 12801919271781.

It is an arithmetic number, because the mean of its divisors is an integer number (12801919271781).

Almost surely, 2^{25603838543561} is an apocalyptic number.

It is an amenable number.

25603838543561 is a deficient number, since it is larger than the sum of its proper divisors (1).

25603838543561 is an equidigital number, since it uses as much as digits as its factorization.

25603838543561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 62208000, while the sum is 59.

The spelling of 25603838543561 in words is "twenty-five trillion, six hundred three billion, eight hundred thirty-eight million, five hundred forty-three thousand, five hundred sixty-one".