1391117051 has 2 divisors, whose sum is σ = 1391117052. Its totient is φ = 1391117050.

The previous prime is 1391117041. The next prime is 1391117059. The reversal of 1391117051 is 1507111931.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1391117051 is a prime.

It is not a weakly prime, because it can be changed into another prime (1391117059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 695558525 + 695558526.

It is an arithmetic number, because the mean of its divisors is an integer number (695558526).

Almost surely, 2^1391117051 is an apocalyptic number.

1391117051 is a deficient number, since it is larger than the sum of its proper divisors (1).

1391117051 is an equidigital number, since it uses as much as digits as its factorization.

1391117051 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 945, while the sum is 29.

The square root of 1391117051 is about 37297.6815767415. The cubic root of 1391117051 is about 1116.3179067488.

Adding to 1391117051 its reverse (1507111931), we get a palindrome (2898228982).

The spelling of 1391117051 in words is "one billion, three hundred ninety-one million, one hundred seventeen thousand, fifty-one".