21340860181 has 2 divisors, whose sum is σ = 21340860182. Its totient is φ = 21340860180.

The previous prime is 21340860127. The next prime is 21340860217. The reversal of 21340860181 is 18106804312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21332063025 + 8797156 = 146055^2 + 2966^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21340860181 is a prime.

It is a super-2 number, since 2×21340860181² (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 (21340860581) 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, 10670430090 + 10670430091.

It is an arithmetic number, because the mean of its divisors is an integer number (10670430091).

Almost surely, 2^21340860181 is an apocalyptic number.

It is an amenable number.

21340860181 is a deficient number, since it is larger than the sum of its proper divisors (1).

21340860181 is an equidigital number, since it uses as much as digits as its factorization.

21340860181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9216, while the sum is 34.

The spelling of 21340860181 in words is "twenty-one billion, three hundred forty million, eight hundred sixty thousand, one hundred eighty-one".