21396082493 has 2 divisors, whose sum is σ = 21396082494. Its totient is φ = 21396082492.

The previous prime is 21396082471. The next prime is 21396082567. The reversal of 21396082493 is 39428069312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20559831769 + 836250724 = 143387^2 + 28918^2 .

It is a cyclic number.

It is not a de Polignac number, because 21396082493 - 2¹² = 21396078397 is a prime.

It is a super-2 number, since 2×21396082493² (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 (21396082453) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10698041246 + 10698041247.

It is an arithmetic number, because the mean of its divisors is an integer number (10698041247).

Almost surely, 2^21396082493 is an apocalyptic number.

It is an amenable number.

21396082493 is a deficient number, since it is larger than the sum of its proper divisors (1).

21396082493 is an equidigital number, since it uses as much as digits as its factorization.

21396082493 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 559872, while the sum is 47.

The spelling of 21396082493 in words is "twenty-one billion, three hundred ninety-six million, eighty-two thousand, four hundred ninety-three".