21011055345 has 40 divisors (see below), whose sum is σ = 43044876864. Its totient is φ = 9605052576.

The previous prime is 21011055337. The next prime is 21011055367. The reversal of 21011055345 is 54355011012.

21011055345 is a `hidden beast` number, since 2 + 10 + 110 + 5 + 534 + 5 = 666.

It is not a de Polignac number, because 21011055345 - 2³ = 21011055337 is a prime.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 3702819 + ... + 3708488.

Almost surely, 2^21011055345 is an apocalyptic number.

It is an amenable number.

21011055345 is an abundant number, since it is smaller than the sum of its proper divisors (22033821519).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21011055345 is an equidigital number, since it uses as much as digits as its factorization.

21011055345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7411331 (or 7411322 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 27.

Adding to 21011055345 its reverse (54355011012), we get a palindrome (75366066357).

The spelling of 21011055345 in words is "twenty-one billion, eleven million, fifty-five thousand, three hundred forty-five".