29997928910821 has 2 divisors, whose sum is σ = 29997928910822. Its totient is φ = 29997928910820.

The previous prime is 29997928910819. The next prime is 29997928910893. The reversal of 29997928910821 is 12801982979992.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18041375180196 + 11956553730625 = 4247514^2 + 3457825^2 .

It is a cyclic number.

It is not a de Polignac number, because 29997928910821 - 2¹ = 29997928910819 is a prime.

It is a super-3 number, since 3×29997928910821³ (a number of 41 digits) contains 333 as substring.

Together with 29997928910819, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (29997928910801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14998964455410 + 14998964455411.

It is an arithmetic number, because the mean of its divisors is an integer number (14998964455411).

Almost surely, 2^{29997928910821} is an apocalyptic number.

It is an amenable number.

29997928910821 is a deficient number, since it is larger than the sum of its proper divisors (1).

29997928910821 is an equidigital number, since it uses as much as digits as its factorization.

29997928910821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 211631616, while the sum is 76.

The spelling of 29997928910821 in words is "twenty-nine trillion, nine hundred ninety-seven billion, nine hundred twenty-eight million, nine hundred ten thousand, eight hundred twenty-one".