6815506621 has 32 divisors (see below), whose sum is σ = 8688992256. Its totient is φ = 5235476400.

The previous prime is 6815506589. The next prime is 6815506661. The reversal of 6815506621 is 1266055186.

It is not a de Polignac number, because 6815506621 - 2⁵ = 6815506589 is a prime.

It is a super-2 number, since 2×6815506621² = 92902261001789675282, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6815506661) 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 31 ways as a sum of consecutive naturals, for example, 656356 + ... + 666658.

It is an arithmetic number, because the mean of its divisors is an integer number (271531008).

Almost surely, 2^6815506621 is an apocalyptic number.

It is an amenable number.

6815506621 is a deficient number, since it is larger than the sum of its proper divisors (1873485635).

6815506621 is a wasteful number, since it uses less digits than its factorization.

6815506621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10414 (or 10392 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 40.

The square root of 6815506621 is about 82556.0816717945. The cubic root of 6815506621 is about 1895.9754722335.

The spelling of 6815506621 in words is "six billion, eight hundred fifteen million, five hundred six thousand, six hundred twenty-one".