1311781357 has 2 divisors, whose sum is σ = 1311781358. Its totient is φ = 1311781356.

The previous prime is 1311781351. The next prime is 1311781369. The reversal of 1311781357 is 7531871131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 760987396 + 550793961 = 27586^2 + 23469^2 .

It is a cyclic number.

It is not a de Polignac number, because 1311781357 - 2¹⁵ = 1311748589 is a prime.

It is a super-2 number, since 2×1311781357² = 3441540657145522898, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1311781351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 655890678 + 655890679.

It is an arithmetic number, because the mean of its divisors is an integer number (655890679).

Almost surely, 2^1311781357 is an apocalyptic number.

It is an amenable number.

1311781357 is a deficient number, since it is larger than the sum of its proper divisors (1).

1311781357 is an equidigital number, since it uses as much as digits as its factorization.

1311781357 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17640, while the sum is 37.

The square root of 1311781357 is about 36218.5222917777. The cubic root of 1311781357 is about 1094.6799192341.

The spelling of 1311781357 in words is "one billion, three hundred eleven million, seven hundred eighty-one thousand, three hundred fifty-seven".