251240420426 has 8 divisors (see below), whose sum is σ = 377678117124. Its totient is φ = 125347714720.

The previous prime is 251240420393. The next prime is 251240420477. The reversal of 251240420426 is 624024042152.

251240420426 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 251146311025 + 94109401 = 501145^2 + 9701^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 251240420392 and 251240420401.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 136246595 + ... + 136248438.

Almost surely, 2^251240420426 is an apocalyptic number.

251240420426 is a deficient number, since it is larger than the sum of its proper divisors (126437696698).

251240420426 is a wasteful number, since it uses less digits than its factorization.

251240420426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 272495496.

The product of its (nonzero) digits is 30720, while the sum is 32.

Adding to 251240420426 its reverse (624024042152), we get a palindrome (875264462578).

The spelling of 251240420426 in words is "two hundred fifty-one billion, two hundred forty million, four hundred twenty thousand, four hundred twenty-six".