667881506 has 4 divisors (see below), whose sum is σ = 1001822262. Its totient is φ = 333940752.

The previous prime is 667881503. The next prime is 667881509. The reversal of 667881506 is 605188766.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (667881503) and next prime (667881509).

It can be written as a sum of positive squares in only one way, i.e., 667447225 + 434281 = 25835^2 + 659^2 .

It is not an unprimeable number, because it can be changed into a prime (667881503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166970375 + ... + 166970378.

Almost surely, 2^667881506 is an apocalyptic number.

667881506 is a deficient number, since it is larger than the sum of its proper divisors (333940756).

667881506 is a wasteful number, since it uses less digits than its factorization.

667881506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333940755.

The product of its (nonzero) digits is 483840, while the sum is 47.

The square root of 667881506 is about 25843.4035297211. The cubic root of 667881506 is about 874.1107727018.

The spelling of 667881506 in words is "six hundred sixty-seven million, eight hundred eighty-one thousand, five hundred six".