21048189845 has 4 divisors (see below), whose sum is σ = 25257827820. Its totient is φ = 16838551872.

The previous prime is 21048189823. The next prime is 21048189863. The reversal of 21048189845 is 54898184012.

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 5148493009 + 15899696836 = 71753^2 + 126094^2 .

It is a cyclic number.

It is not a de Polignac number, because 21048189845 - 2¹⁸ = 21047927701 is a prime.

It is a super-2 number, since 2×21048189845² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21048189793 and 21048189802.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2104818980 + ... + 2104818989.

It is an arithmetic number, because the mean of its divisors is an integer number (6314456955).

Almost surely, 2^21048189845 is an apocalyptic number.

It is an amenable number.

21048189845 is a deficient number, since it is larger than the sum of its proper divisors (4209637975).

21048189845 is an equidigital number, since it uses as much as digits as its factorization.

21048189845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4209637974.

The product of its (nonzero) digits is 737280, while the sum is 50.

The spelling of 21048189845 in words is "twenty-one billion, forty-eight million, one hundred eighty-nine thousand, eight hundred forty-five".