21121313029 has 2 divisors, whose sum is σ = 21121313030. Its totient is φ = 21121313028.

The previous prime is 21121313027. The next prime is 21121313041. The reversal of 21121313029 is 92031312112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18769548004 + 2351765025 = 137002^2 + 48495^2 .

It is a cyclic number.

It is not a de Polignac number, because 21121313029 - 2¹ = 21121313027 is a prime.

It is a super-2 number, since 2×21121313029² (a number of 21 digits) contains 22 as substring.

Together with 21121313027, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 21121312994 and 21121313012.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21121313027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560656514 + 10560656515.

It is an arithmetic number, because the mean of its divisors is an integer number (10560656515).

Almost surely, 2^21121313029 is an apocalyptic number.

It is an amenable number.

21121313029 is a deficient number, since it is larger than the sum of its proper divisors (1).

21121313029 is an equidigital number, since it uses as much as digits as its factorization.

21121313029 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 25.

The spelling of 21121313029 in words is "twenty-one billion, one hundred twenty-one million, three hundred thirteen thousand, twenty-nine".