1257221728 has 48 divisors (see below), whose sum is σ = 2853839520. Its totient is φ = 534030336.

The previous prime is 1257221711. The next prime is 1257221741. The reversal of 1257221728 is 8271227521.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 478 + ... + 50146.

It is an arithmetic number, because the mean of its divisors is an integer number (59454990).

Almost surely, 2^1257221728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1257221728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1426919760).

1257221728 is an abundant number, since it is smaller than the sum of its proper divisors (1596617792).

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

1257221728 is a wasteful number, since it uses less digits than its factorization.

1257221728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49799 (or 49791 counting only the distinct ones).

The product of its digits is 31360, while the sum is 37.

The square root of 1257221728 is about 35457.3226287603. The cubic root of 1257221728 is about 1079.2878615752.

The spelling of 1257221728 in words is "one billion, two hundred fifty-seven million, two hundred twenty-one thousand, seven hundred twenty-eight".