1257110261 has 18 divisors (see below), whose sum is σ = 1420324290. Its totient is φ = 1111793760.

The previous prime is 1257110201. The next prime is 1257110273. The reversal of 1257110261 is 1620117521.

It can be written as a sum of positive squares in 3 ways, for example, as 301682161 + 955428100 = 17369^2 + 30910^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1257110261 is a prime.

It is a super-2 number, since 2×1257110261² = 3160652416622976242, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1257110261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1257110201) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 161855 + ... + 169443.

It is an arithmetic number, because the mean of its divisors is an integer number (78906905).

Almost surely, 2^1257110261 is an apocalyptic number.

1257110261 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1257110261 is a deficient number, since it is larger than the sum of its proper divisors (163214029).

1257110261 is an equidigital number, since it uses as much as digits as its factorization.

1257110261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7685 (or 7637 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 26.

The square root of 1257110261 is about 35455.7507465291. The cubic root of 1257110261 is about 1079.2559635859.

Adding to 1257110261 its reverse (1620117521), we get a palindrome (2877227782).

The spelling of 1257110261 in words is "one billion, two hundred fifty-seven million, one hundred ten thousand, two hundred sixty-one".