213220621 has 4 divisors (see below), whose sum is σ = 213314044. Its totient is φ = 213127200.

The previous prime is 213220619. The next prime is 213220633. The reversal of 213220621 is 126022312.

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 148498596 + 64722025 = 12186^2 + 8045^2 .

It is a cyclic number.

It is not a de Polignac number, because 213220621 - 2¹ = 213220619 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213220661) 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, 43200 + ... + 47881.

It is an arithmetic number, because the mean of its divisors is an integer number (53328511).

Almost surely, 2^213220621 is an apocalyptic number.

It is an amenable number.

213220621 is a deficient number, since it is larger than the sum of its proper divisors (93423).

213220621 is an equidigital number, since it uses as much as digits as its factorization.

213220621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93422.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 213220621 is about 14602.0759140610. The cubic root of 213220621 is about 597.4153831726.

Adding to 213220621 its reverse (126022312), we get a palindrome (339242933).

The spelling of 213220621 in words is "two hundred thirteen million, two hundred twenty thousand, six hundred twenty-one".