68215091 has 4 divisors (see below), whose sum is σ = 77960112. Its totient is φ = 58470072.

The previous prime is 68215061. The next prime is 68215139. The reversal of 68215091 is 19051286.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 68215091 - 2¹⁴ = 68198707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68215061) 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, 4872500 + ... + 4872513.

It is an arithmetic number, because the mean of its divisors is an integer number (19490028).

Almost surely, 2^68215091 is an apocalyptic number.

68215091 is a deficient number, since it is larger than the sum of its proper divisors (9745021).

68215091 is an equidigital number, since it uses as much as digits as its factorization.

68215091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9745020.

The product of its (nonzero) digits is 4320, while the sum is 32.

The square root of 68215091 is about 8259.2427619001. The cubic root of 68215091 is about 408.5954137420.

The spelling of 68215091 in words is "sixty-eight million, two hundred fifteen thousand, ninety-one".