25520135424 has 144 divisors (see below), whose sum is σ = 78102646272. Its totient is φ = 7246485504.

The previous prime is 25520135423. The next prime is 25520135441. The reversal of 25520135424 is 42453102552.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25520135423) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 861727 + ... + 890849.

It is an arithmetic number, because the mean of its divisors is an integer number (542379488).

Almost surely, 2^25520135424 is an apocalyptic number.

25520135424 is a gapful number since it is divisible by the number (24) 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 25520135424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39051323136).

25520135424 is an abundant number, since it is smaller than the sum of its proper divisors (52582510848).

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

25520135424 is a wasteful number, since it uses less digits than its factorization.

25520135424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29312 (or 29298 counting only the distinct ones).

The product of its (nonzero) digits is 48000, while the sum is 33.

Adding to 25520135424 its reverse (42453102552), we get a palindrome (67973237976).

The spelling of 25520135424 in words is "twenty-five billion, five hundred twenty million, one hundred thirty-five thousand, four hundred twenty-four".