1257306240 has 256 divisors, whose sum is σ = 4169531520. Its totient is φ = 322043904.

The previous prime is 1257306233. The next prime is 1257306241. The reversal of 1257306240 is 426037521.

It is a super-2 number, since 2×1257306240² = 3161637962285875200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 1257306198 and 1257306207.

It is not an unprimeable number, because it can be changed into a prime (1257306241) 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 31 ways as a sum of consecutive naturals, for example, 8008242 + ... + 8008398.

Almost surely, 2^1257306240 is an apocalyptic number.

1257306240 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 1257306240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2084765760).

1257306240 is an abundant number, since it is smaller than the sum of its proper divisors (2912225280).

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

1257306240 is a wasteful number, since it uses less digits than its factorization.

1257306240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319 (or 307 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 30.

The square root of 1257306240 is about 35458.5143512810. The cubic root of 1257306240 is about 1079.3120447218.

The spelling of 1257306240 in words is "one billion, two hundred fifty-seven million, three hundred six thousand, two hundred forty".