6613216021 has 2 divisors, whose sum is σ = 6613216022. Its totient is φ = 6613216020.

The previous prime is 6613215953. The next prime is 6613216037. The reversal of 6613216021 is 1206123166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3545607025 + 3067608996 = 59545^2 + 55386^2 .

It is a cyclic number.

It is not a de Polignac number, because 6613216021 - 2¹³ = 6613207829 is a prime.

It is a super-2 number, since 2×6613216021² = 87469252280822144882, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6613216061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3306608010 + 3306608011.

It is an arithmetic number, because the mean of its divisors is an integer number (3306608011).

Almost surely, 2^6613216021 is an apocalyptic number.

It is an amenable number.

6613216021 is a deficient number, since it is larger than the sum of its proper divisors (1).

6613216021 is an equidigital number, since it uses as much as digits as its factorization.

6613216021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 6613216021 is about 81321.6823547078. The cubic root of 6613216021 is about 1877.0286566644.

Adding to 6613216021 its reverse (1206123166), we get a palindrome (7819339187).

The spelling of 6613216021 in words is "six billion, six hundred thirteen million, two hundred sixteen thousand, twenty-one".