251224420 has 12 divisors (see below), whose sum is σ = 527571324. Its totient is φ = 100489760.

The previous prime is 251224411. The next prime is 251224427. The reversal of 251224420 is 24422152.

It can be written as a sum of positive squares in 2 ways, for example, as 28558336 + 222666084 = 5344^2 + 14922^2 .

It is a super-2 number, since 2×251224420² = 126227418408672800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 251224391 and 251224400.

It is not an unprimeable number, because it can be changed into a prime (251224427) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6280591 + ... + 6280630.

It is an arithmetic number, because the mean of its divisors is an integer number (43964277).

Almost surely, 2^251224420 is an apocalyptic number.

251224420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

251224420 is an abundant number, since it is smaller than the sum of its proper divisors (276346904).

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

251224420 is a wasteful number, since it uses less digits than its factorization.

251224420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12561230 (or 12561228 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 22.

The square root of 251224420 is about 15850.0605677076. The cubic root of 251224420 is about 630.9872988520.

Adding to 251224420 its reverse (24422152), we get a palindrome (275646572).

The spelling of 251224420 in words is "two hundred fifty-one million, two hundred twenty-four thousand, four hundred twenty".