21340421512605 has 96 divisors (see below), whose sum is σ = 41527605030912. Its totient is φ = 10066483008000.

The previous prime is 21340421512591. The next prime is 21340421512633. The reversal of 21340421512605 is 50621512404312.

21340421512605 is a `hidden beast` number, since 2 + 1 + 3 + 4 + 0 + 42 + 1 + 5 + 1 + 2 + 605 = 666.

It is not a de Polignac number, because 21340421512605 - 2⁴ = 21340421512589 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21340421512605.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3993877 + ... + 7657146.

It is an arithmetic number, because the mean of its divisors is an integer number (432579219072).

Almost surely, 2^{21340421512605} is an apocalyptic number.

It is an amenable number.

21340421512605 is a deficient number, since it is larger than the sum of its proper divisors (20187183518307).

21340421512605 is a wasteful number, since it uses less digits than its factorization.

21340421512605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11651179 (or 11651176 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

Adding to 21340421512605 its reverse (50621512404312), we get a palindrome (71961933916917).

The spelling of 21340421512605 in words is "twenty-one trillion, three hundred forty billion, four hundred twenty-one million, five hundred twelve thousand, six hundred five".