21403444663 has 2 divisors, whose sum is σ = 21403444664. Its totient is φ = 21403444662.

The previous prime is 21403444637. The next prime is 21403444679. The reversal of 21403444663 is 36644430412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21403444663 - 2⁵ = 21403444631 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21403244663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10701722331 + 10701722332.

It is an arithmetic number, because the mean of its divisors is an integer number (10701722332).

Almost surely, 2^21403444663 is an apocalyptic number.

21403444663 is a deficient number, since it is larger than the sum of its proper divisors (1).

21403444663 is an equidigital number, since it uses as much as digits as its factorization.

21403444663 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 165888, while the sum is 37.

The spelling of 21403444663 in words is "twenty-one billion, four hundred three million, four hundred forty-four thousand, six hundred sixty-three".