25659968921 has 8 divisors (see below), whose sum is σ = 26147443464. Its totient is φ = 25172617600.

The previous prime is 25659968903. The next prime is 25659968933. The reversal of 25659968921 is 12986995652.

It can be written as a sum of positive squares in 4 ways, for example, as 5444816521 + 20215152400 = 73789^2 + 142180^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 25659968921 - 2⁶ = 25659968857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25659968021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 464471 + ... + 516771.

It is an arithmetic number, because the mean of its divisors is an integer number (3268430433).

Almost surely, 2^25659968921 is an apocalyptic number.

It is an amenable number.

25659968921 is a deficient number, since it is larger than the sum of its proper divisors (487474543).

25659968921 is an equidigital number, since it uses as much as digits as its factorization.

25659968921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61611.

The product of its digits is 20995200, while the sum is 62.

The spelling of 25659968921 in words is "twenty-five billion, six hundred fifty-nine million, nine hundred sixty-eight thousand, nine hundred twenty-one".