251240420424 has 32 divisors (see below), whose sum is σ = 717829773120. Its totient is φ = 71782977216.

The previous prime is 251240420393. The next prime is 251240420477. The reversal of 251240420424 is 424024042152.

It is a junction number, because it is equal to n+sod(n) for n = 251240420391 and 251240420400.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 747739179 + ... + 747739514.

It is an arithmetic number, because the mean of its divisors is an integer number (22432180410).

Almost surely, 2^251240420424 is an apocalyptic number.

251240420424 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

251240420424 is an abundant number, since it is smaller than the sum of its proper divisors (466589352696).

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

251240420424 is a wasteful number, since it uses less digits than its factorization.

251240420424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1495478709 (or 1495478705 counting only the distinct ones).

The product of its (nonzero) digits is 20480, while the sum is 30.

Adding to 251240420424 its reverse (424024042152), we get a palindrome (675264462576).

The spelling of 251240420424 in words is "two hundred fifty-one billion, two hundred forty million, four hundred twenty thousand, four hundred twenty-four".