660270640 has 20 divisors (see below), whose sum is σ = 1535129424. Its totient is φ = 264108224.

The previous prime is 660270631. The next prime is 660270647. The reversal of 660270640 is 46072066.

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (660270647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4126612 + ... + 4126771.

Almost surely, 2^660270640 is an apocalyptic number.

It is an amenable number.

660270640 is an abundant number, since it is smaller than the sum of its proper divisors (874858784).

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

660270640 is a wasteful number, since it uses less digits than its factorization.

660270640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8253396 (or 8253390 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 31.

The square root of 660270640 is about 25695.7319413166. The cubic root of 660270640 is about 870.7777604751. Note that the first 4 decimals are identical.

The spelling of 660270640 in words is "six hundred sixty million, two hundred seventy thousand, six hundred forty".