1257856860 has 144 divisors (see below), whose sum is σ = 4038654816. Its totient is φ = 291373056.

The previous prime is 1257856823. The next prime is 1257856883. The reversal of 1257856860 is 686587521.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 168732 + ... + 176028.

It is an arithmetic number, because the mean of its divisors is an integer number (28046214).

Almost surely, 2^1257856860 is an apocalyptic number.

1257856860 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 1257856860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2019327408).

1257856860 is an abundant number, since it is smaller than the sum of its proper divisors (2780797956).

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

1257856860 is a wasteful number, since it uses less digits than its factorization.

1257856860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7352 (or 7337 counting only the distinct ones).

The product of its (nonzero) digits is 806400, while the sum is 48.

The square root of 1257856860 is about 35466.2777860886. The cubic root of 1257856860 is about 1079.4695783564.

The spelling of 1257856860 in words is "one billion, two hundred fifty-seven million, eight hundred fifty-six thousand, eight hundred sixty".