1011231391 has 2 divisors, whose sum is σ = 1011231392. Its totient is φ = 1011231390.

The previous prime is 1011231373. The next prime is 1011231437. The reversal of 1011231391 is 1931321101.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1011231391 - 2¹⁵ = 1011198623 is a prime.

It is a super-2 number, since 2×1011231391² = 2045177852287589762, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1011231341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 505615695 + 505615696.

It is an arithmetic number, because the mean of its divisors is an integer number (505615696).

Almost surely, 2^1011231391 is an apocalyptic number.

1011231391 is a deficient number, since it is larger than the sum of its proper divisors (1).

1011231391 is an equidigital number, since it uses as much as digits as its factorization.

1011231391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 162, while the sum is 22.

The square root of 1011231391 is about 31799.8646380767. The cubic root of 1011231391 is about 1003.7298677897.

Adding to 1011231391 its reverse (1931321101), we get a palindrome (2942552492).

The spelling of 1011231391 in words is "one billion, eleven million, two hundred thirty-one thousand, three hundred ninety-one".