1251121872 has 240 divisors, whose sum is σ = 4365577728. Its totient is φ = 299819520.

The previous prime is 1251121843. The next prime is 1251121873. The reversal of 1251121872 is 2781211521.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1251121873) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 623623 + ... + 625625.

Almost surely, 2^1251121872 is an apocalyptic number.

1251121872 is a gapful number since it is divisible by the number (12) 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 1251121872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2182788864).

1251121872 is an abundant number, since it is smaller than the sum of its proper divisors (3114455856).

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

1251121872 is a wasteful number, since it uses less digits than its factorization.

1251121872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2058 (or 2039 counting only the distinct ones).

The product of its digits is 2240, while the sum is 30.

The square root of 1251121872 is about 35371.2011670511. The cubic root of 1251121872 is about 1077.5395153134.

The spelling of 1251121872 in words is "one billion, two hundred fifty-one million, one hundred twenty-one thousand, eight hundred seventy-two".