1191101531 has 2 divisors, whose sum is σ = 1191101532. Its totient is φ = 1191101530.

The previous prime is 1191101519. The next prime is 1191101539. The reversal of 1191101531 is 1351011911.

It is a strong prime.

It is an emirp because it is prime and its reverse (1351011911) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1191101531 is a prime.

It is a super-2 number, since 2×1191101531² = 2837445714301087922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1191101497 and 1191101506.

It is not a weakly prime, because it can be changed into another prime (1191101539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 595550765 + 595550766.

It is an arithmetic number, because the mean of its divisors is an integer number (595550766).

Almost surely, 2^1191101531 is an apocalyptic number.

1191101531 is a deficient number, since it is larger than the sum of its proper divisors (1).

1191101531 is an equidigital number, since it uses as much as digits as its factorization.

1191101531 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 135, while the sum is 23.

The square root of 1191101531 is about 34512.3388225139. The cubic root of 1191101531 is about 1060.0253734878.

The spelling of 1191101531 in words is "one billion, one hundred ninety-one million, one hundred one thousand, five hundred thirty-one".