251521403131232 has 96 divisors (see below), whose sum is σ = 534225730479840. Its totient is φ = 115879669678080.

The previous prime is 251521403131231. The next prime is 251521403131309. The reversal of 251521403131232 is 232131304125152.

It is a junction number, because it is equal to n+sod(n) for n = 251521403131192 and 251521403131201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251521403131231) 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, 948679007 + ... + 948944097.

It is an arithmetic number, because the mean of its divisors is an integer number (5564851359165).

Almost surely, 2^{251521403131232} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 251521403131232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (267112865239920).

251521403131232 is an abundant number, since it is smaller than the sum of its proper divisors (282704327348608).

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

251521403131232 is a wasteful number, since it uses less digits than its factorization.

251521403131232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 269176 (or 269168 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 35.

Adding to 251521403131232 its reverse (232131304125152), we get a palindrome (483652707256384).

The spelling of 251521403131232 in words is "two hundred fifty-one trillion, five hundred twenty-one billion, four hundred three million, one hundred thirty-one thousand, two hundred thirty-two".