665420210 has 64 divisors (see below), whose sum is σ = 1514080512. Its totient is φ = 204892416.

The previous prime is 665420207. The next prime is 665420233. The reversal of 665420210 is 12024566.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a self number, because there is not a number n which added to its sum of digits gives 665420210.

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, 23789 + ... + 43551.

It is an arithmetic number, because the mean of its divisors is an integer number (23657508).

Almost surely, 2^665420210 is an apocalyptic number.

665420210 is an abundant number, since it is smaller than the sum of its proper divisors (848660302).

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

665420210 is a wasteful number, since it uses less digits than its factorization.

665420210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19827.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 665420210 is about 25795.7401522034. The cubic root of 665420210 is about 873.0356849758.

Adding to 665420210 its reverse (12024566), we get a palindrome (677444776).

The spelling of 665420210 in words is "six hundred sixty-five million, four hundred twenty thousand, two hundred ten".