6601616611221 has 16 divisors (see below), whose sum is σ = 8926635345408. Its totient is φ = 4338844834800.

The previous prime is 6601616611129. The next prime is 6601616611237. The reversal of 6601616611221 is 1221166161066.

It is a happy number.

It is not a de Polignac number, because 6601616611221 - 2¹⁷ = 6601616480149 is a prime.

It is a super-2 number, since 2×6601616611221² (a number of 26 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 6601616611221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6601616611021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2927866 + ... + 4666436.

It is an arithmetic number, because the mean of its divisors is an integer number (557914709088).

Almost surely, 2^{6601616611221} is an apocalyptic number.

It is an amenable number.

6601616611221 is a deficient number, since it is larger than the sum of its proper divisors (2325018734187).

6601616611221 is a wasteful number, since it uses less digits than its factorization.

6601616611221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1756472.

The product of its (nonzero) digits is 31104, while the sum is 39.

The spelling of 6601616611221 in words is "six trillion, six hundred one billion, six hundred sixteen million, six hundred eleven thousand, two hundred twenty-one".