25540512197 has 2 divisors, whose sum is σ = 25540512198. Its totient is φ = 25540512196.

The previous prime is 25540512187. The next prime is 25540512229. The reversal of 25540512197 is 79121504552.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25174899556 + 365612641 = 158666^2 + 19121^2 .

It is a cyclic number.

It is not a de Polignac number, because 25540512197 - 2¹⁰ = 25540511173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25540512187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12770256098 + 12770256099.

It is an arithmetic number, because the mean of its divisors is an integer number (12770256099).

Almost surely, 2^25540512197 is an apocalyptic number.

It is an amenable number.

25540512197 is a deficient number, since it is larger than the sum of its proper divisors (1).

25540512197 is an equidigital number, since it uses as much as digits as its factorization.

25540512197 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 126000, while the sum is 41.

The spelling of 25540512197 in words is "twenty-five billion, five hundred forty million, five hundred twelve thousand, one hundred ninety-seven".