667761642 has 12 divisors (see below), whose sum is σ = 1446816930. Its totient is φ = 222587208.

The previous prime is 667761637. The next prime is 667761709. The reversal of 667761642 is 246167766.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 629457921 + 38303721 = 25089^2 + 6189^2 .

It is a super-2 number, since 2×667761642² = 891811221053072328, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 18548917 + ... + 18548952.

Almost surely, 2^667761642 is an apocalyptic number.

667761642 is an abundant number, since it is smaller than the sum of its proper divisors (779055288).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

667761642 is a wasteful number, since it uses less digits than its factorization.

667761642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37097877 (or 37097874 counting only the distinct ones).

The product of its digits is 508032, while the sum is 45.

The square root of 667761642 is about 25841.0843812716. The cubic root of 667761642 is about 874.0584776558.

The spelling of 667761642 in words is "six hundred sixty-seven million, seven hundred sixty-one thousand, six hundred forty-two".