668181487 has 6 divisors (see below), whose sum is σ = 698496512. Its totient is φ = 639129612.

The previous prime is 668181439. The next prime is 668181539. The reversal of 668181487 is 784181866.

It is a happy number.

It is not a de Polignac number, because 668181487 - 2⁷ = 668181359 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 668181487.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668181887) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 631023 + ... + 632080.

Almost surely, 2^668181487 is an apocalyptic number.

668181487 is a deficient number, since it is larger than the sum of its proper divisors (30315025).

668181487 is a wasteful number, since it uses less digits than its factorization.

668181487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1263149 (or 1263126 counting only the distinct ones).

The product of its digits is 516096, while the sum is 49.

The square root of 668181487 is about 25849.2066996262. The cubic root of 668181487 is about 874.2416229463.

The spelling of 668181487 in words is "six hundred sixty-eight million, one hundred eighty-one thousand, four hundred eighty-seven".