1391356009 has 2 divisors, whose sum is σ = 1391356010. Its totient is φ = 1391356008.

The previous prime is 1391355967. The next prime is 1391356039. The reversal of 1391356009 is 9006531931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1075512025 + 315843984 = 32795^2 + 17772^2 .

It is an emirp because it is prime and its reverse (9006531931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1391356009 - 2¹³ = 1391347817 is a prime.

It is not a weakly prime, because it can be changed into another prime (1391356039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 695678004 + 695678005.

It is an arithmetic number, because the mean of its divisors is an integer number (695678005).

Almost surely, 2^1391356009 is an apocalyptic number.

It is an amenable number.

1391356009 is a deficient number, since it is larger than the sum of its proper divisors (1).

1391356009 is an equidigital number, since it uses as much as digits as its factorization.

1391356009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21870, while the sum is 37.

The square root of 1391356009 is about 37300.8848286472. The cubic root of 1391356009 is about 1116.3818212895.

The spelling of 1391356009 in words is "one billion, three hundred ninety-one million, three hundred fifty-six thousand, nine".