21100145305 has 8 divisors (see below), whose sum is σ = 25402652352. Its totient is φ = 16825130928.

The previous prime is 21100145303. The next prime is 21100145309. The reversal of 21100145305 is 50354100112.

It is a happy number.

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 21100145305 - 2¹ = 21100145303 is a prime.

It is a super-2 number, since 2×21100145305² (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 (21100145303) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6871477 + ... + 6874546.

It is an arithmetic number, because the mean of its divisors is an integer number (3175331544).

Almost surely, 2^21100145305 is an apocalyptic number.

It is an amenable number.

21100145305 is a deficient number, since it is larger than the sum of its proper divisors (4302507047).

21100145305 is a wasteful number, since it uses less digits than its factorization.

21100145305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13746335.

The product of its (nonzero) digits is 600, while the sum is 22.

Adding to 21100145305 its reverse (50354100112), we get a palindrome (71454245417).

The spelling of 21100145305 in words is "twenty-one billion, one hundred million, one hundred forty-five thousand, three hundred five".