25520421 has 8 divisors (see below), whose sum is σ = 34236640. Its totient is φ = 16908912.

The previous prime is 25520419. The next prime is 25520423. The reversal of 25520421 is 12402552.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (25520419) and next prime (25520423).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 25520421 - 2¹ = 25520419 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25520423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25606 + ... + 26583.

It is an arithmetic number, because the mean of its divisors is an integer number (4279580).

Almost surely, 2^25520421 is an apocalyptic number.

It is an amenable number.

25520421 is a deficient number, since it is larger than the sum of its proper divisors (8716219).

25520421 is a wasteful number, since it uses less digits than its factorization.

25520421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52355.

The product of its (nonzero) digits is 800, while the sum is 21.

The square root of 25520421 is about 5051.7740448282. The cubic root of 25520421 is about 294.4168158826.

Adding to 25520421 its reverse (12402552), we get a palindrome (37922973).

The spelling of 25520421 in words is "twenty-five million, five hundred twenty thousand, four hundred twenty-one".