667220121 has 12 divisors (see below), whose sum is σ = 986176048. Its totient is φ = 434468664.

The previous prime is 667220117. The next prime is 667220123. The reversal of 667220121 is 121022766.

It is not a de Polignac number, because 667220121 - 2² = 667220117 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (667220123) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 861655 + ... + 862428.

Almost surely, 2^667220121 is an apocalyptic number.

It is an amenable number.

667220121 is a deficient number, since it is larger than the sum of its proper divisors (318955927).

667220121 is a wasteful number, since it uses less digits than its factorization.

667220121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1724132 (or 1724129 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 667220121 is about 25830.6043483307. The cubic root of 667220121 is about 873.8221413170.

Adding to 667220121 its reverse (121022766), we get a palindrome (788242887).

The spelling of 667220121 in words is "six hundred sixty-seven million, two hundred twenty thousand, one hundred twenty-one".