1381681757 has 2 divisors, whose sum is σ = 1381681758. Its totient is φ = 1381681756.

The previous prime is 1381681753. The next prime is 1381681793. The reversal of 1381681757 is 7571861831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1347330436 + 34351321 = 36706^2 + 5861^2 .

It is a cyclic number.

It is not a de Polignac number, because 1381681757 - 2² = 1381681753 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1381681753) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 690840878 + 690840879.

It is an arithmetic number, because the mean of its divisors is an integer number (690840879).

Almost surely, 2^1381681757 is an apocalyptic number.

It is an amenable number.

1381681757 is a deficient number, since it is larger than the sum of its proper divisors (1).

1381681757 is an equidigital number, since it uses as much as digits as its factorization.

1381681757 is an evil number, because the sum of its binary digits is even.

The product of its digits is 282240, while the sum is 47.

The square root of 1381681757 is about 37170.9800381965. The cubic root of 1381681757 is about 1113.7883590586.

The spelling of 1381681757 in words is "one billion, three hundred eighty-one million, six hundred eighty-one thousand, seven hundred fifty-seven".