6621606381 has 16 divisors (see below), whose sum is σ = 10008367040. Its totient is φ = 3860369280.

The previous prime is 6621606377. The next prime is 6621606487. The reversal of 6621606381 is 1836061266.

6621606381 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 6621606381 - 2² = 6621606377 is a prime.

It is a super-2 number, since 2×6621606381² = 87691342129799834322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6621606311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4467280 + ... + 4468761.

It is an arithmetic number, because the mean of its divisors is an integer number (625522940).

Almost surely, 2^6621606381 is an apocalyptic number.

It is an amenable number.

6621606381 is a deficient number, since it is larger than the sum of its proper divisors (3386760659).

6621606381 is a wasteful number, since it uses less digits than its factorization.

6621606381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8936076.

The product of its (nonzero) digits is 62208, while the sum is 39.

The square root of 6621606381 is about 81373.2534743450. The cubic root of 6621606381 is about 1877.8221329616.

The spelling of 6621606381 in words is "six billion, six hundred twenty-one million, six hundred six thousand, three hundred eighty-one".