25443635381 has 2 divisors, whose sum is σ = 25443635382. Its totient is φ = 25443635380.

The previous prime is 25443635369. The next prime is 25443635383. The reversal of 25443635381 is 18353634452.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24178695025 + 1264940356 = 155495^2 + 35566^2 .

It is a cyclic number.

It is not a de Polignac number, because 25443635381 - 2¹⁴ = 25443618997 is a prime.

It is a super-2 number, since 2×25443635381² (a number of 22 digits) contains 22 as substring.

Together with 25443635383, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25443635383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12721817690 + 12721817691.

It is an arithmetic number, because the mean of its divisors is an integer number (12721817691).

Almost surely, 2^25443635381 is an apocalyptic number.

It is an amenable number.

25443635381 is a deficient number, since it is larger than the sum of its proper divisors (1).

25443635381 is an equidigital number, since it uses as much as digits as its factorization.

25443635381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1036800, while the sum is 44.

The spelling of 25443635381 in words is "twenty-five billion, four hundred forty-three million, six hundred thirty-five thousand, three hundred eighty-one".