29991917 has 2 divisors, whose sum is σ = 29991918. Its totient is φ = 29991916.

The previous prime is 29991889. The next prime is 29991919. The reversal of 29991917 is 71919992.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23174596 + 6817321 = 4814^2 + 2611^2 .

It is a cyclic number.

It is not a de Polignac number, because 29991917 - 2¹² = 29987821 is a prime.

Together with 29991919, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (29991919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14995958 + 14995959.

It is an arithmetic number, because the mean of its divisors is an integer number (14995959).

Almost surely, 2^29991917 is an apocalyptic number.

It is an amenable number.

29991917 is a deficient number, since it is larger than the sum of its proper divisors (1).

29991917 is an equidigital number, since it uses as much as digits as its factorization.

29991917 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 91854, while the sum is 47.

The square root of 29991917 is about 5476.4876517710. The cubic root of 29991917 is about 310.6953416883.

The spelling of 29991917 in words is "twenty-nine million, nine hundred ninety-one thousand, nine hundred seventeen".