666521002 has 16 divisors (see below), whose sum is σ = 1192286592. Its totient is φ = 273232080.

The previous prime is 666520961. The next prime is 666521017. The reversal of 666521002 is 200125666.

It is a super-2 number, since 2×666521002² = 888500492214168008, which contains 22 as substring.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 1034649 + ... + 1035292.

It is an arithmetic number, because the mean of its divisors is an integer number (74517912).

Almost surely, 2^666521002 is an apocalyptic number.

666521002 is a deficient number, since it is larger than the sum of its proper divisors (525765590).

666521002 is a wasteful number, since it uses less digits than its factorization.

666521002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2069973.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 666521002 is about 25817.0680364754. The cubic root of 666521002 is about 873.5168351982.

Adding to 666521002 its reverse (200125666), we get a palindrome (866646668).

The spelling of 666521002 in words is "six hundred sixty-six million, five hundred twenty-one thousand, two".