21354100605 has 64 divisors (see below), whose sum is σ = 41492736000. Its totient is φ = 10373114880.

The previous prime is 21354100583. The next prime is 21354100681. The reversal of 21354100605 is 50600145312.

21354100605 is a `hidden beast` number, since 2 + 1 + 3 + 54 + 1 + 0 + 0 + 605 = 666.

It is not a de Polignac number, because 21354100605 - 2¹² = 21354096509 is a prime.

It is a super-2 number, since 2×21354100605² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 78930 + ... + 221219.

It is an arithmetic number, because the mean of its divisors is an integer number (648324000).

Almost surely, 2^21354100605 is an apocalyptic number.

It is an amenable number.

21354100605 is a deficient number, since it is larger than the sum of its proper divisors (20138635395).

21354100605 is a wasteful number, since it uses less digits than its factorization.

21354100605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300211 (or 300205 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

Adding to 21354100605 its reverse (50600145312), we get a palindrome (71954245917).

The spelling of 21354100605 in words is "twenty-one billion, three hundred fifty-four million, one hundred thousand, six hundred five".