1191431 has 2 divisors, whose sum is σ = 1191432. Its totient is φ = 1191430.

The previous prime is 1191409. The next prime is 1191439. The reversal of 1191431 is 1341911.

It is a strong prime.

It is an emirp because it is prime and its reverse (1341911) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1191431 is a prime.

It is a super-2 number, since 2×1191431² = 2839015655522, which contains 22 as substring.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1191439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 595715 + 595716.

It is an arithmetic number, because the mean of its divisors is an integer number (595716).

2^1191431 is an apocalyptic number.

1191431 is a deficient number, since it is larger than the sum of its proper divisors (1).

1191431 is an equidigital number, since it uses as much as digits as its factorization.

1191431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108, while the sum is 20.

The square root of 1191431 is about 1091.5269121740. The cubic root of 1191431 is about 106.0123101877.

The spelling of 1191431 in words is "one million, one hundred ninety-one thousand, four hundred thirty-one".