251630533242 has 24 divisors (see below), whose sum is σ = 594763079040. Its totient is φ = 76251676680.

The previous prime is 251630533237. The next prime is 251630533243. The reversal of 251630533242 is 242335036152.

251630533242 is a `hidden beast` number, since 2 + 5 + 16 + 305 + 332 + 4 + 2 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 251630533197 and 251630533206.

It is not an unprimeable number, because it can be changed into a prime (251630533243) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 635430442 + ... + 635430837.

It is an arithmetic number, because the mean of its divisors is an integer number (24781794960).

Almost surely, 2^251630533242 is an apocalyptic number.

251630533242 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

251630533242 is an abundant number, since it is smaller than the sum of its proper divisors (343132545798).

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

251630533242 is a wasteful number, since it uses less digits than its factorization.

251630533242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1270861298 (or 1270861295 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 36.

Adding to 251630533242 its reverse (242335036152), we get a palindrome (493965569394).

The spelling of 251630533242 in words is "two hundred fifty-one billion, six hundred thirty million, five hundred thirty-three thousand, two hundred forty-two".