667653532778 has 8 divisors (see below), whose sum is σ = 1001496094272. Its totient is φ = 333821501356.

The previous prime is 667653532771. The next prime is 667653532781. The reversal of 667653532778 is 877235356766.

It is a happy number.

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

It is a super-2 number, since 2×667653532778² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (667653532771) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 2472050 + ... + 2728797.

It is an arithmetic number, because the mean of its divisors is an integer number (125187011784).

Almost surely, 2^667653532778 is an apocalyptic number.

667653532778 is a deficient number, since it is larger than the sum of its proper divisors (333842561494).

667653532778 is a wasteful number, since it uses less digits than its factorization.

667653532778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5265036.

The product of its digits is 266716800, while the sum is 65.

The spelling of 667653532778 in words is "six hundred sixty-seven billion, six hundred fifty-three million, five hundred thirty-two thousand, seven hundred seventy-eight".