25664240421 has 8 divisors (see below), whose sum is σ = 38021096960. Its totient is φ = 17109493596.

The previous prime is 25664240419. The next prime is 25664240447. The reversal of 25664240421 is 12404246652.

25664240421 is a `hidden beast` number, since 2 + 5 + 6 + 642 + 4 + 0 + 4 + 2 + 1 = 666.

It is not a de Polignac number, because 25664240421 - 2¹ = 25664240419 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 (25664240221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 475263685 + ... + 475263738.

It is an arithmetic number, because the mean of its divisors is an integer number (4752637120).

Almost surely, 2^25664240421 is an apocalyptic number.

It is an amenable number.

25664240421 is a deficient number, since it is larger than the sum of its proper divisors (12356856539).

25664240421 is an equidigital number, since it uses as much as digits as its factorization.

25664240421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 950527432 (or 950527426 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 36.

It can be divided in two parts, 25664 and 240421, that added together give a triangular number (266085 = T₇₂₉).

The spelling of 25664240421 in words is "twenty-five billion, six hundred sixty-four million, two hundred forty thousand, four hundred twenty-one".