21514400981 has 2 divisors, whose sum is σ = 21514400982. Its totient is φ = 21514400980.

The previous prime is 21514400959. The next prime is 21514401023. The reversal of 21514400981 is 18900441512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20819604100 + 694796881 = 144290^2 + 26359^2 .

It is a cyclic number.

It is not a de Polignac number, because 21514400981 - 2¹⁴ = 21514384597 is a prime.

It is a super-2 number, since 2×21514400981² (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 (21514406981) 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, 10757200490 + 10757200491.

It is an arithmetic number, because the mean of its divisors is an integer number (10757200491).

Almost surely, 2^21514400981 is an apocalyptic number.

It is an amenable number.

21514400981 is a deficient number, since it is larger than the sum of its proper divisors (1).

21514400981 is an equidigital number, since it uses as much as digits as its factorization.

21514400981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11520, while the sum is 35.

The spelling of 21514400981 in words is "twenty-one billion, five hundred fourteen million, four hundred thousand, nine hundred eighty-one".