21051023893 has 2 divisors, whose sum is σ = 21051023894. Its totient is φ = 21051023892.

The previous prime is 21051023869. The next prime is 21051023921. The reversal of 21051023893 is 39832015012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20846161924 + 204861969 = 144382^2 + 14313^2 .

It is a cyclic number.

It is not a de Polignac number, because 21051023893 - 2¹³ = 21051015701 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21051023843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10525511946 + 10525511947.

It is an arithmetic number, because the mean of its divisors is an integer number (10525511947).

Almost surely, 2^21051023893 is an apocalyptic number.

It is an amenable number.

21051023893 is a deficient number, since it is larger than the sum of its proper divisors (1).

21051023893 is an equidigital number, since it uses as much as digits as its factorization.

21051023893 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 34.

The spelling of 21051023893 in words is "twenty-one billion, fifty-one million, twenty-three thousand, eight hundred ninety-three".