616001221 has 4 divisors (see below), whose sum is σ = 672001344. Its totient is φ = 560001100.

The previous prime is 616001219. The next prime is 616001227. The reversal of 616001221 is 122100616.

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 616001221 - 2¹ = 616001219 is a prime.

It is a Duffinian number.

616001221 is a modest number, since divided by 1221 gives 616 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (616001227) 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, 28000045 + ... + 28000066.

It is an arithmetic number, because the mean of its divisors is an integer number (168000336).

Almost surely, 2^616001221 is an apocalyptic number.

It is an amenable number.

616001221 is a deficient number, since it is larger than the sum of its proper divisors (56000123).

616001221 is a wasteful number, since it uses less digits than its factorization.

616001221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56000122.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 616001221 is about 24819.3718897155. The cubic root of 616001221 is about 850.8647352007.

Adding to 616001221 its reverse (122100616), we get a palindrome (738101837).

The spelling of 616001221 in words is "six hundred sixteen million, one thousand, two hundred twenty-one".