105305817821 has 8 divisors (see below), whose sum is σ = 107889271224. Its totient is φ = 102723079680.

The previous prime is 105305817817. The next prime is 105305817823. The reversal of 105305817821 is 128718503501.

It can be written as a sum of positive squares in 4 ways, for example, as 5089252921 + 100216564900 = 71339^2 + 316570^2 .

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 105305817821 - 2² = 105305817817 is a prime.

It is a super-2 number, since 2×105305817821² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (105305817823) 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, 125525 + ... + 475781.

It is an arithmetic number, because the mean of its divisors is an integer number (13486158903).

Almost surely, 2^105305817821 is an apocalyptic number.

It is an amenable number.

105305817821 is a deficient number, since it is larger than the sum of its proper divisors (2583453403).

105305817821 is an equidigital number, since it uses as much as digits as its factorization.

105305817821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 357631.

The product of its (nonzero) digits is 67200, while the sum is 41.

The spelling of 105305817821 in words is "one hundred five billion, three hundred five million, eight hundred seventeen thousand, eight hundred twenty-one".