291616 has 24 divisors (see below), whose sum is σ = 619164. Its totient is φ = 134400.

The previous prime is 291569. The next prime is 291619. The reversal of 291616 is 616192.

It can be written as a sum of positive squares in 2 ways, for example, as 291600 + 16 = 540^2 + 4^2 .

It is not an unprimeable number, because it can be changed into a prime (291619) by changing a digit.

291616 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66 + ... + 766.

2²⁹¹⁶¹⁶ is an apocalyptic number.

291616 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 291616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (309582).

291616 is an abundant number, since it is smaller than the sum of its proper divisors (327548).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

291616 is a wasteful number, since it uses less digits than its factorization.

291616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 724 (or 716 counting only the distinct ones).

The product of its digits is 648, while the sum is 25.

The square root of 291616 is about 540.0148146116. The cubic root of 291616 is about 66.3137798032.

It can be divided in two parts, 2916 and 16, that multiplied together give a 6-th power (46656 = 6⁶).

The spelling of 291616 in words is "two hundred ninety-one thousand, six hundred sixteen".