6521151666 has 16 divisors (see below), whose sum is σ = 13043210688. Its totient is φ = 2173566000.

The previous prime is 6521151653. The next prime is 6521151673. The reversal of 6521151666 is 6661511256.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 87651 + ... + 143961.

It is an arithmetic number, because the mean of its divisors is an integer number (815200668).

Almost surely, 2^6521151666 is an apocalyptic number.

6521151666 is an abundant number, since it is smaller than the sum of its proper divisors (6522059022).

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

6521151666 is a wasteful number, since it uses less digits than its factorization.

6521151666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75617.

The product of its digits is 64800, while the sum is 39.

The square root of 6521151666 is about 80753.6480042852. The cubic root of 6521151666 is about 1868.2777155356.

The spelling of 6521151666 in words is "six billion, five hundred twenty-one million, one hundred fifty-one thousand, six hundred sixty-six".