21384938051 has 2 divisors, whose sum is σ = 21384938052. Its totient is φ = 21384938050.

The previous prime is 21384938039. The next prime is 21384938087. The reversal of 21384938051 is 15083948312.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21384938051 is a prime.

It is a super-3 number, since 3×21384938051³ (a number of 32 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 21384937993 and 21384938011.

It is not a weakly prime, because it can be changed into another prime (21384938251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10692469025 + 10692469026.

It is an arithmetic number, because the mean of its divisors is an integer number (10692469026).

Almost surely, 2^21384938051 is an apocalyptic number.

21384938051 is a deficient number, since it is larger than the sum of its proper divisors (1).

21384938051 is an equidigital number, since it uses as much as digits as its factorization.

21384938051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 207360, while the sum is 44.

The spelling of 21384938051 in words is "twenty-one billion, three hundred eighty-four million, nine hundred thirty-eight thousand, fifty-one".