251215024420 has 24 divisors (see below), whose sum is σ = 527565496248. Its totient is φ = 100483353600.

The previous prime is 251215024387. The next prime is 251215024427. The reversal of 251215024420 is 24420512152.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 135862336 + 251079162084 = 11656^2 + 501078^2 .

It is not an unprimeable number, because it can be changed into a prime (251215024427) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 726580 + ... + 1015060.

It is an arithmetic number, because the mean of its divisors is an integer number (21981895677).

Almost surely, 2^251215024420 is an apocalyptic number.

251215024420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

251215024420 is an abundant number, since it is smaller than the sum of its proper divisors (276350471828).

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

251215024420 is a wasteful number, since it uses less digits than its factorization.

251215024420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332031 (or 332029 counting only the distinct ones).

The product of its (nonzero) digits is 6400, while the sum is 28.

Adding to 251215024420 its reverse (24420512152), we get a palindrome (275635536572).

The spelling of 251215024420 in words is "two hundred fifty-one billion, two hundred fifteen million, twenty-four thousand, four hundred twenty".