1029990121 has 2 divisors, whose sum is σ = 1029990122. Its totient is φ = 1029990120.

The previous prime is 1029990119. The next prime is 1029990131. The reversal of 1029990121 is 1210999201.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 989794521 + 40195600 = 31461^2 + 6340^2 .

It is an emirp because it is prime and its reverse (1210999201) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1029990121 - 2¹ = 1029990119 is a prime.

Together with 1029990119, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1029990131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 514995060 + 514995061.

It is an arithmetic number, because the mean of its divisors is an integer number (514995061).

Almost surely, 2^1029990121 is an apocalyptic number.

It is an amenable number.

1029990121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1029990121 is an equidigital number, since it uses as much as digits as its factorization.

1029990121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2916, while the sum is 34.

The square root of 1029990121 is about 32093.4591622654. The cubic root of 1029990121 is about 1009.8984052959.

The spelling of 1029990121 in words is "one billion, twenty-nine million, nine hundred ninety thousand, one hundred twenty-one".