25520321 has 2 divisors, whose sum is σ = 25520322. Its totient is φ = 25520320.

The previous prime is 25520309. The next prime is 25520329. The reversal of 25520321 is 12302552.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21520321 + 4000000 = 4639^2 + 2000^2 .

It is a cyclic number.

It is not a de Polignac number, because 25520321 - 2¹⁰ = 25519297 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 25520293 and 25520302.

It is not a weakly prime, because it can be changed into another prime (25520329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12760160 + 12760161.

It is an arithmetic number, because the mean of its divisors is an integer number (12760161).

Almost surely, 2^25520321 is an apocalyptic number.

It is an amenable number.

25520321 is a deficient number, since it is larger than the sum of its proper divisors (1).

25520321 is an equidigital number, since it uses as much as digits as its factorization.

25520321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 600, while the sum is 20.

The square root of 25520321 is about 5051.7641473054. The cubic root of 25520321 is about 294.4164313315.

Adding to 25520321 its reverse (12302552), we get a palindrome (37822873).

The spelling of 25520321 in words is "twenty-five million, five hundred twenty thousand, three hundred twenty-one".