21345108107 has 4 divisors (see below), whose sum is σ = 21355788000. Its totient is φ = 21334428216.

The previous prime is 21345108053. The next prime is 21345108121. The reversal of 21345108107 is 70180154312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21345108107 - 2¹⁰ = 21345107083 is a prime.

It is a super-2 number, since 2×21345108107² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21345108157) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5336948 + ... + 5340945.

It is an arithmetic number, because the mean of its divisors is an integer number (5338947000).

Almost surely, 2^21345108107 is an apocalyptic number.

21345108107 is a deficient number, since it is larger than the sum of its proper divisors (10679893).

21345108107 is a wasteful number, since it uses less digits than its factorization.

21345108107 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10679892.

The product of its (nonzero) digits is 6720, while the sum is 32.

The spelling of 21345108107 in words is "twenty-one billion, three hundred forty-five million, one hundred eight thousand, one hundred seven".