21517482439 has 2 divisors, whose sum is σ = 21517482440. Its totient is φ = 21517482438.

The previous prime is 21517482433. The next prime is 21517482457. The reversal of 21517482439 is 93428471512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21517482439 - 2³ = 21517482431 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21517482431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10758741219 + 10758741220.

It is an arithmetic number, because the mean of its divisors is an integer number (10758741220).

Almost surely, 2^21517482439 is an apocalyptic number.

21517482439 is a deficient number, since it is larger than the sum of its proper divisors (1).

21517482439 is an equidigital number, since it uses as much as digits as its factorization.

21517482439 is an evil number, because the sum of its binary digits is even.

The product of its digits is 483840, while the sum is 46.

The spelling of 21517482439 in words is "twenty-one billion, five hundred seventeen million, four hundred eighty-two thousand, four hundred thirty-nine".