34639921 has 2 divisors, whose sum is σ = 34639922. Its totient is φ = 34639920.

The previous prime is 34639919. The next prime is 34639939. The reversal of 34639921 is 12993643.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31528225 + 3111696 = 5615^2 + 1764^2 .

It is a cyclic number.

It is not a de Polignac number, because 34639921 - 2¹ = 34639919 is a prime.

Together with 34639919, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (34639991) by changing a digit.

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 as a sum of consecutive naturals, namely, 17319960 + 17319961.

It is an arithmetic number, because the mean of its divisors is an integer number (17319961).

Almost surely, 2^34639921 is an apocalyptic number.

It is an amenable number.

34639921 is a deficient number, since it is larger than the sum of its proper divisors (1).

34639921 is an equidigital number, since it uses as much as digits as its factorization.

34639921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34992, while the sum is 37.

The square root of 34639921 is about 5885.5688764978. The cubic root of 34639921 is about 325.9810074624.

The spelling of 34639921 in words is "thirty-four million, six hundred thirty-nine thousand, nine hundred twenty-one".