21055000049 has 4 divisors (see below), whose sum is σ = 21055320036. Its totient is φ = 21054680064.

The previous prime is 21055000039. The next prime is 21055000051. The reversal of 21055000049 is 94000055012.

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

It can be written as a sum of positive squares in 2 ways, for example, as 11247663025 + 9807337024 = 106055^2 + 99032^2 .

It is a cyclic number.

It is not a de Polignac number, because 21055000049 - 2⁴ = 21055000033 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21054999991 and 21055000027.

It is not an unprimeable number, because it can be changed into a prime (21055000039) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21104 + ... + 206289.

It is an arithmetic number, because the mean of its divisors is an integer number (5263830009).

Almost surely, 2^21055000049 is an apocalyptic number.

It is an amenable number.

21055000049 is a deficient number, since it is larger than the sum of its proper divisors (319987).

21055000049 is an equidigital number, since it uses as much as digits as its factorization.

21055000049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 319986.

The product of its (nonzero) digits is 1800, while the sum is 26.

The spelling of 21055000049 in words is "twenty-one billion, fifty-five million, forty-nine", and thus it is an aban number and an uban number.