660251987 has 8 divisors (see below), whose sum is σ = 676734912. Its totient is φ = 643787200.

The previous prime is 660251959. The next prime is 660252011. The reversal of 660251987 is 789152066.

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 660251987 - 2⁶ = 660251923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (660251927) 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, 97037 + ... + 103617.

It is an arithmetic number, because the mean of its divisors is an integer number (84591864).

Almost surely, 2^660251987 is an apocalyptic number.

660251987 is a deficient number, since it is larger than the sum of its proper divisors (16482925).

660251987 is a wasteful number, since it uses less digits than its factorization.

660251987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9069.

The product of its (nonzero) digits is 181440, while the sum is 44.

The square root of 660251987 is about 25695.3689796430. The cubic root of 660251987 is about 870.7695604182.

The spelling of 660251987 in words is "six hundred sixty million, two hundred fifty-one thousand, nine hundred eighty-seven".