21478138519 has 2 divisors, whose sum is σ = 21478138520. Its totient is φ = 21478138518.

The previous prime is 21478138501. The next prime is 21478138567. The reversal of 21478138519 is 91583187412.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21478138519 is a prime.

It is a super-2 number, since 2×21478138519² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21478138919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10739069259 + 10739069260.

It is an arithmetic number, because the mean of its divisors is an integer number (10739069260).

Almost surely, 2^21478138519 is an apocalyptic number.

21478138519 is a deficient number, since it is larger than the sum of its proper divisors (1).

21478138519 is an equidigital number, since it uses as much as digits as its factorization.

21478138519 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 483840, while the sum is 49.

The spelling of 21478138519 in words is "twenty-one billion, four hundred seventy-eight million, one hundred thirty-eight thousand, five hundred nineteen".