251530420 has 24 divisors (see below), whose sum is σ = 528512544. Its totient is φ = 100555296.

The previous prime is 251530381. The next prime is 251530439. The reversal of 251530420 is 24035152.

It is a junction number, because it is equal to n+sod(n) for n = 251530391 and 251530400.

It is a congruent number.

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, 64239 + ... + 68041.

It is an arithmetic number, because the mean of its divisors is an integer number (22021356).

Almost surely, 2^251530420 is an apocalyptic number.

251530420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

251530420 is an abundant number, since it is smaller than the sum of its proper divisors (276982124).

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

251530420 is a wasteful number, since it uses less digits than its factorization.

251530420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7119 (or 7117 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 251530420 is about 15859.7105900455. The cubic root of 251530420 is about 631.2433829977.

Adding to 251530420 its reverse (24035152), we get a palindrome (275565572).

The spelling of 251530420 in words is "two hundred fifty-one million, five hundred thirty thousand, four hundred twenty".