665215320 has 128 divisors (see below), whose sum is σ = 2488112640. Its totient is φ = 138224640.

The previous prime is 665215301. The next prime is 665215333. The reversal of 665215320 is 23512566.

It is a super-2 number, since 2×665215320² = 885022843925404800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

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, 26757 + ... + 45236.

It is an arithmetic number, because the mean of its divisors is an integer number (19438380).

Almost surely, 2^665215320 is an apocalyptic number.

665215320 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

665215320 is an abundant number, since it is smaller than the sum of its proper divisors (1822897320).

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

665215320 is a wasteful number, since it uses less digits than its factorization.

665215320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72025 (or 72021 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 30.

The square root of 665215320 is about 25791.7684542956. The cubic root of 665215320 is about 872.9460701023.

Adding to 665215320 its reverse (23512566), we get a palindrome (688727886).

The spelling of 665215320 in words is "six hundred sixty-five million, two hundred fifteen thousand, three hundred twenty".