21300021943 has 2 divisors, whose sum is σ = 21300021944. Its totient is φ = 21300021942.

The previous prime is 21300021931. The next prime is 21300021959. The reversal of 21300021943 is 34912000312.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21300021943 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21300021923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10650010971 + 10650010972.

It is an arithmetic number, because the mean of its divisors is an integer number (10650010972).

Almost surely, 2^21300021943 is an apocalyptic number.

21300021943 is a deficient number, since it is larger than the sum of its proper divisors (1).

21300021943 is an equidigital number, since it uses as much as digits as its factorization.

21300021943 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 25.

The spelling of 21300021943 in words is "twenty-one billion, three hundred million, twenty-one thousand, nine hundred forty-three".