21404043293 has 2 divisors, whose sum is σ = 21404043294. Its totient is φ = 21404043292.

The previous prime is 21404043277. The next prime is 21404043373. The reversal of 21404043293 is 39234040412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13692042169 + 7712001124 = 117013^2 + 87818^2 .

It is a cyclic number.

It is not a de Polignac number, because 21404043293 - 2⁴ = 21404043277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21404043203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10702021646 + 10702021647.

It is an arithmetic number, because the mean of its divisors is an integer number (10702021647).

Almost surely, 2^21404043293 is an apocalyptic number.

It is an amenable number.

21404043293 is a deficient number, since it is larger than the sum of its proper divisors (1).

21404043293 is an equidigital number, since it uses as much as digits as its factorization.

21404043293 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20736, while the sum is 32.

The spelling of 21404043293 in words is "twenty-one billion, four hundred four million, forty-three thousand, two hundred ninety-three".