667221707 has 4 divisors (see below), whose sum is σ = 667709040. Its totient is φ = 666734376.

The previous prime is 667221701. The next prime is 667221739. The reversal of 667221707 is 707122766.

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

It is a cyclic number.

It is not a de Polignac number, because 667221707 - 2⁴ = 667221691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (667221701) 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, 241607 + ... + 244352.

It is an arithmetic number, because the mean of its divisors is an integer number (166927260).

Almost surely, 2^667221707 is an apocalyptic number.

667221707 is a deficient number, since it is larger than the sum of its proper divisors (487333).

667221707 is a wasteful number, since it uses less digits than its factorization.

667221707 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 487332.

The product of its (nonzero) digits is 49392, while the sum is 38.

The square root of 667221707 is about 25830.6350483297. The cubic root of 667221707 is about 873.8228336826.

The spelling of 667221707 in words is "six hundred sixty-seven million, two hundred twenty-one thousand, seven hundred seven".