21102043493 has 2 divisors, whose sum is σ = 21102043494. Its totient is φ = 21102043492.

The previous prime is 21102043489. The next prime is 21102043507. The reversal of 21102043493 is 39434020112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15247804324 + 5854239169 = 123482^2 + 76513^2 .

It is a cyclic number.

It is not a de Polignac number, because 21102043493 - 2² = 21102043489 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21102043433) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10551021746 + 10551021747.

It is an arithmetic number, because the mean of its divisors is an integer number (10551021747).

Almost surely, 2^21102043493 is an apocalyptic number.

It is an amenable number.

21102043493 is a deficient number, since it is larger than the sum of its proper divisors (1).

21102043493 is an equidigital number, since it uses as much as digits as its factorization.

21102043493 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 29.

The spelling of 21102043493 in words is "twenty-one billion, one hundred two million, forty-three thousand, four hundred ninety-three".