91068815 has 4 divisors (see below), whose sum is σ = 109282584. Its totient is φ = 72855048.

The previous prime is 91068811. The next prime is 91068821. The reversal of 91068815 is 51886019.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 51886019 = 71 ⋅730789.

It is a cyclic number.

It is not a de Polignac number, because 91068815 - 2² = 91068811 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 (91068811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9106877 + ... + 9106886.

It is an arithmetic number, because the mean of its divisors is an integer number (27320646).

Almost surely, 2^91068815 is an apocalyptic number.

91068815 is a deficient number, since it is larger than the sum of its proper divisors (18213769).

91068815 is a wasteful number, since it uses less digits than its factorization.

91068815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18213768.

The product of its (nonzero) digits is 17280, while the sum is 38.

The square root of 91068815 is about 9542.9982185894. The cubic root of 91068815 is about 449.9074953888.

The spelling of 91068815 in words is "ninety-one million, sixty-eight thousand, eight hundred fifteen".