1078389691 has 2 divisors, whose sum is σ = 1078389692. Its totient is φ = 1078389690.

The previous prime is 1078389671. The next prime is 1078389743. The reversal of 1078389691 is 1969838701.

It is a happy number.

It is an a-pointer prime, because the next prime (1078389743) can be obtained adding 1078389691 to its sum of digits (52).

It is a weak prime.

It is an emirp because it is prime and its reverse (1969838701) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1078389691 is a prime.

It is not a weakly prime, because it can be changed into another prime (1078389601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 539194845 + 539194846.

It is an arithmetic number, because the mean of its divisors is an integer number (539194846).

Almost surely, 2^1078389691 is an apocalyptic number.

1078389691 is a deficient number, since it is larger than the sum of its proper divisors (1).

1078389691 is an equidigital number, since it uses as much as digits as its factorization.

1078389691 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 653184, while the sum is 52.

The square root of 1078389691 is about 32838.8442397110. The cubic root of 1078389691 is about 1025.4753903486.

The spelling of 1078389691 in words is "one billion, seventy-eight million, three hundred eighty-nine thousand, six hundred ninety-one".