660405387 has 8 divisors (see below), whose sum is σ = 897154704. Its totient is φ = 431963168.

The previous prime is 660405331. The next prime is 660405397. The reversal of 660405387 is 783504066.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 660405387 - 2¹⁸ = 660143243 is a prime.

It is a super-2 number, since 2×660405387² = 872270550357239538, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (660405397) 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, 2076588 + ... + 2076905.

It is an arithmetic number, because the mean of its divisors is an integer number (112144338).

Almost surely, 2^660405387 is an apocalyptic number.

660405387 is a deficient number, since it is larger than the sum of its proper divisors (236749317).

660405387 is a wasteful number, since it uses less digits than its factorization.

660405387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4153549.

The product of its (nonzero) digits is 120960, while the sum is 39.

The square root of 660405387 is about 25698.3537799603. The cubic root of 660405387 is about 870.8369921007.

The spelling of 660405387 in words is "six hundred sixty million, four hundred five thousand, three hundred eighty-seven".