1257166728 has 48 divisors (see below), whose sum is σ = 3605113980. Its totient is φ = 394404864.

The previous prime is 1257166717. The next prime is 1257166817. The reversal of 1257166728 is 8276617521.

1257166728 is a `hidden beast` number, since 1 + 2 + 571 + 6 + 6 + 72 + 8 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1251885924 + 5280804 = 35382^2 + 2298^2 .

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 11 ways as a sum of consecutive naturals, for example, 512325 + ... + 514772.

Almost surely, 2^1257166728 is an apocalyptic number.

1257166728 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1257166728 is an abundant number, since it is smaller than the sum of its proper divisors (2347947252).

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

1257166728 is a wasteful number, since it uses less digits than its factorization.

1257166728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1027126 (or 1027119 counting only the distinct ones).

The product of its digits is 282240, while the sum is 45.

The square root of 1257166728 is about 35456.5470400038. The cubic root of 1257166728 is about 1079.2721227184.

The spelling of 1257166728 in words is "one billion, two hundred fifty-seven million, one hundred sixty-six thousand, seven hundred twenty-eight".