11531533787 has 2 divisors, whose sum is σ = 11531533788. Its totient is φ = 11531533786.

The previous prime is 11531533771. The next prime is 11531533877. The reversal of 11531533787 is 78733513511.

Together with next prime (11531533877) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 11531533787 - 2⁴ = 11531533771 is a prime.

It is a super-2 number, since 2×11531533787² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (11531533747) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5765766893 + 5765766894.

It is an arithmetic number, because the mean of its divisors is an integer number (5765766894).

Almost surely, 2^11531533787 is an apocalyptic number.

11531533787 is a deficient number, since it is larger than the sum of its proper divisors (1).

11531533787 is an equidigital number, since it uses as much as digits as its factorization.

11531533787 is an evil number, because the sum of its binary digits is even.

The product of its digits is 264600, while the sum is 44.

The spelling of 11531533787 in words is "eleven billion, five hundred thirty-one million, five hundred thirty-three thousand, seven hundred eighty-seven".