21430663247 has 4 divisors (see below), whose sum is σ = 24492186576. Its totient is φ = 18369139920.

The previous prime is 21430663237. The next prime is 21430663249. The reversal of 21430663247 is 74236603412.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21430663247 - 2⁶ = 21430663183 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21430663247.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21430663249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1530761654 + ... + 1530761667.

It is an arithmetic number, because the mean of its divisors is an integer number (6123046644).

Almost surely, 2^21430663247 is an apocalyptic number.

21430663247 is a deficient number, since it is larger than the sum of its proper divisors (3061523329).

21430663247 is an equidigital number, since it uses as much as digits as its factorization.

21430663247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3061523328.

The product of its (nonzero) digits is 145152, while the sum is 38.

The spelling of 21430663247 in words is "twenty-one billion, four hundred thirty million, six hundred sixty-three thousand, two hundred forty-seven".