21040334389 has 2 divisors, whose sum is σ = 21040334390. Its totient is φ = 21040334388.

The previous prime is 21040334377. The next prime is 21040334401. The reversal of 21040334389 is 98343304012.

It is a balanced prime because it is at equal distance from previous prime (21040334377) and next prime (21040334401).

It can be written as a sum of positive squares in only one way, i.e., 18052072164 + 2988262225 = 134358^2 + 54665^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21040334389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21040334089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10520167194 + 10520167195.

It is an arithmetic number, because the mean of its divisors is an integer number (10520167195).

Almost surely, 2^21040334389 is an apocalyptic number.

It is an amenable number.

21040334389 is a deficient number, since it is larger than the sum of its proper divisors (1).

21040334389 is an equidigital number, since it uses as much as digits as its factorization.

21040334389 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 62208, while the sum is 37.

The spelling of 21040334389 in words is "twenty-one billion, forty million, three hundred thirty-four thousand, three hundred eighty-nine".