1011231191 has 16 divisors (see below), whose sum is σ = 1057452288. Its totient is φ = 965952000.

The previous prime is 1011231163. The next prime is 1011231197. The reversal of 1011231191 is 1911321101.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1011231191 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1011231197) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 841391 + ... + 842591.

It is an arithmetic number, because the mean of its divisors is an integer number (66090768).

Almost surely, 2^1011231191 is an apocalyptic number.

1011231191 is a deficient number, since it is larger than the sum of its proper divisors (46221097).

1011231191 is a wasteful number, since it uses less digits than its factorization.

1011231191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1562.

The product of its (nonzero) digits is 54, while the sum is 20.

The square root of 1011231191 is about 31799.8614934091. The cubic root of 1011231191 is about 1003.7298016176.

Adding to 1011231191 its reverse (1911321101), we get a palindrome (2922552292).

The spelling of 1011231191 in words is "one billion, eleven million, two hundred thirty-one thousand, one hundred ninety-one".