25438165641 has 64 divisors (see below), whose sum is σ = 43349852160. Its totient is φ = 14441976000.

The previous prime is 25438165639. The next prime is 25438165651. The reversal of 25438165641 is 14656183452.

25438165641 is a `hidden beast` number, since 2 + 5 + 4 + 3 + 81 + 6 + 564 + 1 = 666.

It is not a de Polignac number, because 25438165641 - 2¹ = 25438165639 is a prime.

It is not an unprimeable number, because it can be changed into a prime (25438165651) 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 63 ways as a sum of consecutive naturals, for example, 33872016 + ... + 33872766.

It is an arithmetic number, because the mean of its divisors is an integer number (677341440).

Almost surely, 2^25438165641 is an apocalyptic number.

25438165641 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

25438165641 is a deficient number, since it is larger than the sum of its proper divisors (17911686519).

25438165641 is a wasteful number, since it uses less digits than its factorization.

25438165641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1691 (or 1685 counting only the distinct ones).

The product of its digits is 691200, while the sum is 45.

The spelling of 25438165641 in words is "twenty-five billion, four hundred thirty-eight million, one hundred sixty-five thousand, six hundred forty-one".