660243555 has 40 divisors (see below), whose sum is σ = 1200269664. Its totient is φ = 347155200.

The previous prime is 660243517. The next prime is 660243581. The reversal of 660243555 is 555342066.

It is a happy number.

660243555 is a `hidden beast` number, since 6 + 60 + 2 + 43 + 555 = 666.

It is not a de Polignac number, because 660243555 - 2⁶ = 660243491 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 17275 + ... + 40235.

Almost surely, 2^660243555 is an apocalyptic number.

660243555 is a deficient number, since it is larger than the sum of its proper divisors (540026109).

660243555 is a wasteful number, since it uses less digits than its factorization.

660243555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23049 (or 23040 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 36.

The square root of 660243555 is about 25695.2049028608. The cubic root of 660243555 is about 870.7658535707.

The spelling of 660243555 in words is "six hundred sixty million, two hundred forty-three thousand, five hundred fifty-five".