21038000209 has 8 divisors (see below), whose sum is σ = 21229251912. Its totient is φ = 20846837760.

The previous prime is 21038000197. The next prime is 21038000219. The reversal of 21038000209 is 90200083012.

It can be written as a sum of positive squares in 4 ways, for example, as 1264015809 + 19773984400 = 35553^2 + 140620^2 .

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 21038000209 - 2¹⁷ = 21037869137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21038000219) 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, 508129 + ... + 547969.

It is an arithmetic number, because the mean of its divisors is an integer number (2653656489).

Almost surely, 2^21038000209 is an apocalyptic number.

It is an amenable number.

21038000209 is a deficient number, since it is larger than the sum of its proper divisors (191251703).

21038000209 is a wasteful number, since it uses less digits than its factorization.

21038000209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44627.

The product of its (nonzero) digits is 864, while the sum is 25.

The spelling of 21038000209 in words is "twenty-one billion, thirty-eight million, two hundred nine", and thus it is an aban number.