6656633820 has 36 divisors (see below), whose sum is σ = 20191789800. Its totient is φ = 1775102304.

The previous prime is 6656633783. The next prime is 6656633857. The reversal of 6656633820 is 283366566.

6656633820 is a `hidden beast` number, since 6 + 6 + 5 + 6 + 633 + 8 + 2 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (6656633783) and next prime (6656633857).

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18490470 + ... + 18490829.

It is an arithmetic number, because the mean of its divisors is an integer number (560883050).

Almost surely, 2^6656633820 is an apocalyptic number.

6656633820 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6656633820 is an abundant number, since it is smaller than the sum of its proper divisors (13535155980).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6656633820 is a wasteful number, since it uses less digits than its factorization.

6656633820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36981314 (or 36981309 counting only the distinct ones).

The product of its (nonzero) digits is 933120, while the sum is 45.

The square root of 6656633820 is about 81588.1965727886. The cubic root of 6656633820 is about 1881.1274567330.

The spelling of 6656633820 in words is "six billion, six hundred fifty-six million, six hundred thirty-three thousand, eight hundred twenty".