6611645621 has 16 divisors (see below), whose sum is σ = 7808547840. Its totient is φ = 5478243840.

The previous prime is 6611645603. The next prime is 6611645639. The reversal of 6611645621 is 1265461166.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (6611645603) and next prime (6611645639).

It is a cyclic number.

It is not a de Polignac number, because 6611645621 - 2²² = 6607451317 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6611645671) 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, 185195 + ... + 217991.

It is an arithmetic number, because the mean of its divisors is an integer number (488034240).

Almost surely, 2^6611645621 is an apocalyptic number.

It is an amenable number.

6611645621 is a deficient number, since it is larger than the sum of its proper divisors (1196902219).

6611645621 is a wasteful number, since it uses less digits than its factorization.

6611645621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33764.

The product of its digits is 51840, while the sum is 38.

The square root of 6611645621 is about 81312.0262999269. The cubic root of 6611645621 is about 1876.8800693937.

The spelling of 6611645621 in words is "six billion, six hundred eleven million, six hundred forty-five thousand, six hundred twenty-one".