34208721 has 18 divisors (see below), whose sum is σ = 52155090. Its totient is φ = 21603456.

The previous prime is 34208701. The next prime is 34208729. The reversal of 34208721 is 12780243.

It can be written as a sum of positive squares in only one way, i.e., 32490000 + 1718721 = 5700^2 + 1311^2 .

It is not a de Polignac number, because 34208721 - 2¹⁰ = 34207697 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (34208729) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 2016 + ... + 8513.

It is an arithmetic number, because the mean of its divisors is an integer number (2897505).

Almost surely, 2^34208721 is an apocalyptic number.

It is an amenable number.

34208721 is a deficient number, since it is larger than the sum of its proper divisors (17946369).

34208721 is a wasteful number, since it uses less digits than its factorization.

34208721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10573 (or 10551 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 34208721 is about 5848.8221891249. The cubic root of 34208721 is about 324.6227449004.

Adding to 34208721 its reverse (12780243), we get a palindrome (46988964).

The spelling of 34208721 in words is "thirty-four million, two hundred eight thousand, seven hundred twenty-one".