6721493655 has 32 divisors (see below), whose sum is σ = 11023133184. Its totient is φ = 3496029056.

The previous prime is 6721493617. The next prime is 6721493657. The reversal of 6721493655 is 5563941276.

It is a cyclic number.

It is not a de Polignac number, because 6721493655 - 2²⁰ = 6720445079 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6721493657) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 107452 + ... + 158078.

It is an arithmetic number, because the mean of its divisors is an integer number (344472912).

Almost surely, 2^6721493655 is an apocalyptic number.

6721493655 is a deficient number, since it is larger than the sum of its proper divisors (4301639529).

6721493655 is a wasteful number, since it uses less digits than its factorization.

6721493655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50855.

The product of its digits is 1360800, while the sum is 48.

The square root of 6721493655 is about 81984.7159841394. The cubic root of 6721493655 is about 1887.2173954041.

The spelling of 6721493655 in words is "six billion, seven hundred twenty-one million, four hundred ninety-three thousand, six hundred fifty-five".