1081291639 has 2 divisors, whose sum is σ = 1081291640. Its totient is φ = 1081291638.

The previous prime is 1081291591. The next prime is 1081291649. The reversal of 1081291639 is 9361921801.

It is a strong prime.

It is an emirp because it is prime and its reverse (9361921801) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1081291639 - 2¹⁹ = 1080767351 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1081291649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 540645819 + 540645820.

It is an arithmetic number, because the mean of its divisors is an integer number (540645820).

Almost surely, 2^1081291639 is an apocalyptic number.

1081291639 is a deficient number, since it is larger than the sum of its proper divisors (1).

1081291639 is an equidigital number, since it uses as much as digits as its factorization.

1081291639 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 1081291639 is about 32882.9992397287. Note that the first 3 decimals coincide. The cubic root of 1081291639 is about 1026.3944183228.

The spelling of 1081291639 in words is "one billion, eighty-one million, two hundred ninety-one thousand, six hundred thirty-nine".