25438446640 has 40 divisors (see below), whose sum is σ = 59165664048. Its totient is φ = 10171718400.

The previous prime is 25438446601. The next prime is 25438446653. The reversal of 25438446640 is 4664483452.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×25438446640² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

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, 172314 + ... + 283846.

Almost surely, 2^25438446640 is an apocalyptic number.

25438446640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25438446640 is an abundant number, since it is smaller than the sum of its proper divisors (33727217408).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

25438446640 is a wasteful number, since it uses less digits than its factorization.

25438446640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114397 (or 114391 counting only the distinct ones).

The product of its (nonzero) digits is 2211840, while the sum is 46.

The spelling of 25438446640 in words is "twenty-five billion, four hundred thirty-eight million, four hundred forty-six thousand, six hundred forty".