25378391820 has 96 divisors (see below), whose sum is σ = 74640706560. Its totient is φ = 6430406400.

The previous prime is 25378391803. The next prime is 25378391821. The reversal of 25378391820 is 2819387352.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 25378391820.

It is not an unprimeable number, because it can be changed into a prime (25378391821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 147486 + ... + 269274.

It is an arithmetic number, because the mean of its divisors is an integer number (777507360).

Almost surely, 2^25378391820 is an apocalyptic number.

25378391820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25378391820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37320353280).

25378391820 is an abundant number, since it is smaller than the sum of its proper divisors (49262314740).

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

25378391820 is a wasteful number, since it uses less digits than its factorization.

25378391820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121975 (or 121973 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 48.

The spelling of 25378391820 in words is "twenty-five billion, three hundred seventy-eight million, three hundred ninety-one thousand, eight hundred twenty".