665655790 has 16 divisors (see below), whose sum is σ = 1217823840. Its totient is φ = 261897120.

The previous prime is 665655761. The next prime is 665655797. The reversal of 665655790 is 97556566.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665655797) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 545010 + ... + 546229.

It is an arithmetic number, because the mean of its divisors is an integer number (76113990).

Almost surely, 2^665655790 is an apocalyptic number.

665655790 is a deficient number, since it is larger than the sum of its proper divisors (552168050).

665655790 is a wasteful number, since it uses less digits than its factorization.

665655790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1091307.

The product of its (nonzero) digits is 1701000, while the sum is 49.

The square root of 665655790 is about 25800.3060059372. The cubic root of 665655790 is about 873.1387003222.

The spelling of 665655790 in words is "six hundred sixty-five million, six hundred fifty-five thousand, seven hundred ninety".