1251323320 has 128 divisors (see below), whose sum is σ = 3161592000. Its totient is φ = 445186560.

The previous prime is 1251323279. The next prime is 1251323327. The reversal of 1251323320 is 233231521.

It is a junction number, because it is equal to n+sod(n) for n = 1251323291 and 1251323300.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1251323327) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2548275 + ... + 2548765.

Almost surely, 2^1251323320 is an apocalyptic number.

1251323320 is a gapful number since it is divisible by the number (10) 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 1251323320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1580796000).

1251323320 is an abundant number, since it is smaller than the sum of its proper divisors (1910268680).

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

1251323320 is a wasteful number, since it uses less digits than its factorization.

1251323320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 570 (or 540 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 22.

The square root of 1251323320 is about 35374.0486797878. The cubic root of 1251323320 is about 1077.5973451529.

Adding to 1251323320 its reverse (233231521), we get a palindrome (1484554841).

The spelling of 1251323320 in words is "one billion, two hundred fifty-one million, three hundred twenty-three thousand, three hundred twenty".