21055052305 has 12 divisors (see below), whose sum is σ = 29391134580. Its totient is φ = 14437749984.

The previous prime is 21055052303. The next prime is 21055052321. The reversal of 21055052305 is 50325055012.

It can be written as a sum of positive squares in 2 ways, for example, as 11452424256 + 9602628049 = 107016^2 + 97993^2 .

It is not a de Polignac number, because 21055052305 - 2¹ = 21055052303 is a prime.

It is a super-3 number, since 3×21055052305³ (a number of 32 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21055052303) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 42969250 + ... + 42969739.

It is an arithmetic number, because the mean of its divisors is an integer number (2449261215).

Almost surely, 2^21055052305 is an apocalyptic number.

It is an amenable number.

21055052305 is a deficient number, since it is larger than the sum of its proper divisors (8336082275).

21055052305 is an equidigital number, since it uses as much as digits as its factorization.

21055052305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85939008 (or 85939001 counting only the distinct ones).

The product of its (nonzero) digits is 7500, while the sum is 28.

The spelling of 21055052305 in words is "twenty-one billion, fifty-five million, fifty-two thousand, three hundred five".