1251208728 has 288 divisors, whose sum is σ = 4448530800. Its totient is φ = 324656640.

The previous prime is 1251208709. The next prime is 1251208753. The reversal of 1251208728 is 8278021521.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1251208692 and 1251208701.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1280176 + ... + 1281152.

Almost surely, 2^1251208728 is an apocalyptic number.

1251208728 is a gapful number since it is divisible by the number (18) 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 1251208728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2224265400).

1251208728 is an abundant number, since it is smaller than the sum of its proper divisors (3197322072).

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

1251208728 is a wasteful number, since it uses less digits than its factorization.

1251208728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1028 (or 1000 counting only the distinct ones).

The product of its (nonzero) digits is 17920, while the sum is 36.

The square root of 1251208728 is about 35372.4289242342. The cubic root of 1251208728 is about 1077.5644498964.

The spelling of 1251208728 in words is "one billion, two hundred fifty-one million, two hundred eight thousand, seven hundred twenty-eight".