25561147 has 2 divisors, whose sum is σ = 25561148. Its totient is φ = 25561146.

The previous prime is 25561139. The next prime is 25561189. The reversal of 25561147 is 74116552.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 25561147 - 2³ = 25561139 is a prime.

It is not a weakly prime, because it can be changed into another prime (25561247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12780573 + 12780574.

It is an arithmetic number, because the mean of its divisors is an integer number (12780574).

Almost surely, 2^25561147 is an apocalyptic number.

25561147 is a deficient number, since it is larger than the sum of its proper divisors (1).

25561147 is an equidigital number, since it uses as much as digits as its factorization.

25561147 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8400, while the sum is 31.

The square root of 25561147 is about 5055.8032991801. The cubic root of 25561147 is about 294.5733447360.

Adding to 25561147 its reverse (74116552), we get a palindrome (99677699).

The spelling of 25561147 in words is "twenty-five million, five hundred sixty-one thousand, one hundred forty-seven".