21013114981 has 2 divisors, whose sum is σ = 21013114982. Its totient is φ = 21013114980.

The previous prime is 21013114957. The next prime is 21013115003. The reversal of 21013114981 is 18941131012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13776890625 + 7236224356 = 117375^2 + 85066^2 .

It is a cyclic number.

It is not a de Polignac number, because 21013114981 - 2⁷ = 21013114853 is a prime.

It is a super-2 number, since 2×21013114981² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21013114921) 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, 10506557490 + 10506557491.

It is an arithmetic number, because the mean of its divisors is an integer number (10506557491).

Almost surely, 2^21013114981 is an apocalyptic number.

It is an amenable number.

21013114981 is a deficient number, since it is larger than the sum of its proper divisors (1).

21013114981 is an equidigital number, since it uses as much as digits as its factorization.

21013114981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 31.

Adding to 21013114981 its reverse (18941131012), we get a palindrome (39954245993).

The spelling of 21013114981 in words is "twenty-one billion, thirteen million, one hundred fourteen thousand, nine hundred eighty-one".