21380388751 has 2 divisors, whose sum is σ = 21380388752. Its totient is φ = 21380388750.

The previous prime is 21380388703. The next prime is 21380388767. The reversal of 21380388751 is 15788308312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21380388751 - 2¹⁹ = 21379864463 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21380388781) 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 as a sum of consecutive naturals, namely, 10690194375 + 10690194376.

It is an arithmetic number, because the mean of its divisors is an integer number (10690194376).

Almost surely, 2^21380388751 is an apocalyptic number.

21380388751 is a deficient number, since it is larger than the sum of its proper divisors (1).

21380388751 is an equidigital number, since it uses as much as digits as its factorization.

21380388751 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 322560, while the sum is 46.

The spelling of 21380388751 in words is "twenty-one billion, three hundred eighty million, three hundred eighty-eight thousand, seven hundred fifty-one".