21605372339459 has 8 divisors (see below), whose sum is σ = 21646003991040. Its totient is φ = 21564750457800.

The previous prime is 21605372339431. The next prime is 21605372339533. The reversal of 21605372339459 is 95493327350612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21605372339459 - 2³² = 21601077372163 is a prime.

It is a super-2 number, since 2×21605372339459² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21605372339398 and 21605372339407.

It is not an unprimeable number, because it can be changed into a prime (21605372839459) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1992074 + ... + 6868704.

It is an arithmetic number, because the mean of its divisors is an integer number (2705750498880).

Almost surely, 2^{21605372339459} is an apocalyptic number.

21605372339459 is a deficient number, since it is larger than the sum of its proper divisors (40631651581).

21605372339459 is an equidigital number, since it uses as much as digits as its factorization.

21605372339459 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4884961.

The product of its (nonzero) digits is 36741600, while the sum is 59.

The spelling of 21605372339459 in words is "twenty-one trillion, six hundred five billion, three hundred seventy-two million, three hundred thirty-nine thousand, four hundred fifty-nine".