668610215 has 32 divisors (see below), whose sum is σ = 989283456. Its totient is φ = 422438400.

The previous prime is 668610143. The next prime is 668610223. The reversal of 668610215 is 512016866.

It is a happy number.

It is not a de Polignac number, because 668610215 - 2¹⁸ = 668348071 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 350765 + ... + 352665.

It is an arithmetic number, because the mean of its divisors is an integer number (30915108).

Almost surely, 2^668610215 is an apocalyptic number.

668610215 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

668610215 is a deficient number, since it is larger than the sum of its proper divisors (320673241).

668610215 is a wasteful number, since it uses less digits than its factorization.

668610215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2699.

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 668610215 is about 25857.4982355215. The cubic root of 668610215 is about 874.4285640366.

The spelling of 668610215 in words is "six hundred sixty-eight million, six hundred ten thousand, two hundred fifteen".