10815991 has 2 divisors, whose sum is σ = 10815992. Its totient is φ = 10815990.

The previous prime is 10815983. The next prime is 10816027. The reversal of 10815991 is 19951801.

10815991 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is an emirp because it is prime and its reverse (19951801) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 10815991 - 2³ = 10815983 is a prime.

It is a super-2 number, since 2×10815991² = 233971322624162, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (10815901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5407995 + 5407996.

It is an arithmetic number, because the mean of its divisors is an integer number (5407996).

Almost surely, 2^10815991 is an apocalyptic number.

10815991 is a deficient number, since it is larger than the sum of its proper divisors (1).

10815991 is an equidigital number, since it uses as much as digits as its factorization.

10815991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3240, while the sum is 34.

The square root of 10815991 is about 3288.7673982816. The cubic root of 10815991 is about 221.1509312072.

It can be divided in two parts, 1081599 and 1, that added together give a square (1081600 = 1040²).

The spelling of 10815991 in words is "ten million, eight hundred fifteen thousand, nine hundred ninety-one".