21004220213 has 4 divisors (see below), whose sum is σ = 21010781088. Its totient is φ = 20997659340.

The previous prime is 21004220203. The next prime is 21004220227. The reversal of 21004220213 is 31202240012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21004220213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21004220191 and 21004220200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21004220203) 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, 3275633 + ... + 3282038.

It is an arithmetic number, because the mean of its divisors is an integer number (5252695272).

Almost surely, 2^21004220213 is an apocalyptic number.

It is an amenable number.

21004220213 is a deficient number, since it is larger than the sum of its proper divisors (6560875).

21004220213 is an equidigital number, since it uses as much as digits as its factorization.

21004220213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6560874.

The product of its (nonzero) digits is 192, while the sum is 17.

Adding to 21004220213 its reverse (31202240012), we get a palindrome (52206460225).

The spelling of 21004220213 in words is "twenty-one billion, four million, two hundred twenty thousand, two hundred thirteen".