251223120 has 120 divisors (see below), whose sum is σ = 875006496. Its totient is φ = 66987648.

The previous prime is 251223097. The next prime is 251223169. The reversal of 251223120 is 21322152.

It is a tau number, because it is divible by the number of its divisors (120).

It is a super-2 number, since 2×251223120² = 126226112045068800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 251223093 and 251223102.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12979 + ... + 25901.

Almost surely, 2^251223120 is an apocalyptic number.

251223120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 251223120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (437503248).

251223120 is an abundant number, since it is smaller than the sum of its proper divisors (623783376).

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

251223120 is a wasteful number, since it uses less digits than its factorization.

251223120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12951 (or 12933 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 251223120 is about 15850.0195583476. The cubic root of 251223120 is about 630.9862104693.

Adding to 251223120 its reverse (21322152), we get a palindrome (272545272).

The spelling of 251223120 in words is "two hundred fifty-one million, two hundred twenty-three thousand, one hundred twenty".