25718535217 has 2 divisors, whose sum is σ = 25718535218. Its totient is φ = 25718535216.

The previous prime is 25718535211. The next prime is 25718535277. The reversal of 25718535217 is 71253581752.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22146201856 + 3572333361 = 148816^2 + 59769^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25718535217 is a prime.

It is a super-3 number, since 3×25718535217³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (25718535211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12859267608 + 12859267609.

It is an arithmetic number, because the mean of its divisors is an integer number (12859267609).

Almost surely, 2^25718535217 is an apocalyptic number.

It is an amenable number.

25718535217 is a deficient number, since it is larger than the sum of its proper divisors (1).

25718535217 is an equidigital number, since it uses as much as digits as its factorization.

25718535217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 588000, while the sum is 46.

It can be divided in two parts, 257185352 and 17, that added together give a square (257185369 = 16037²).

The spelling of 25718535217 in words is "twenty-five billion, seven hundred eighteen million, five hundred thirty-five thousand, two hundred seventeen".