616535221 has 4 divisors (see below), whose sum is σ = 617438592. Its totient is φ = 615631852.

The previous prime is 616535207. The next prime is 616535251. The reversal of 616535221 is 122535616.

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 not a de Polignac number, because 616535221 - 2⁷ = 616535093 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 (616535251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 450661 + ... + 452026.

It is an arithmetic number, because the mean of its divisors is an integer number (154359648).

Almost surely, 2^616535221 is an apocalyptic number.

It is an amenable number.

616535221 is a deficient number, since it is larger than the sum of its proper divisors (903371).

616535221 is an equidigital number, since it uses as much as digits as its factorization.

616535221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 903370.

The product of its digits is 10800, while the sum is 31.

The square root of 616535221 is about 24830.1272852154. The cubic root of 616535221 is about 851.1105304599.

The spelling of 616535221 in words is "six hundred sixteen million, five hundred thirty-five thousand, two hundred twenty-one".