25663453421 has 4 divisors (see below), whose sum is σ = 25664114112. Its totient is φ = 25662792732.

The previous prime is 25663453397. The next prime is 25663453427. The reversal of 25663453421 is 12435436652.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 25663453421 - 2¹⁸ = 25663191277 is a prime.

It is a super-5 number, since 5×25663453421⁵ (a number of 53 digits) contains 55555 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25663453427) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 268181 + ... + 351066.

It is an arithmetic number, because the mean of its divisors is an integer number (6416028528).

Almost surely, 2^25663453421 is an apocalyptic number.

It is an amenable number.

25663453421 is a deficient number, since it is larger than the sum of its proper divisors (660691).

25663453421 is an equidigital number, since it uses as much as digits as its factorization.

25663453421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 660690.

The product of its digits is 518400, while the sum is 41.

The spelling of 25663453421 in words is "twenty-five billion, six hundred sixty-three million, four hundred fifty-three thousand, four hundred twenty-one".