6666442 has 4 divisors (see below), whose sum is σ = 9999666. Its totient is φ = 3333220.

The previous prime is 6666437. The next prime is 6666449. The reversal of 6666442 is 2446666.

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

It can be written as a sum of positive squares in only one way, i.e., 4198401 + 2468041 = 2049^2 + 1571^2 .

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 6666398 and 6666407.

It is not an unprimeable number, because it can be changed into a prime (6666449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1666609 + ... + 1666612.

Almost surely, 2^6666442 is an apocalyptic number.

6666442 is a deficient number, since it is larger than the sum of its proper divisors (3333224).

6666442 is a wasteful number, since it uses less digits than its factorization.

6666442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3333223.

The product of its digits is 41472, while the sum is 34.

The square root of 6666442 is about 2581.9453905921. The cubic root of 6666442 is about 188.2050915582.

The spelling of 6666442 in words is "six million, six hundred sixty-six thousand, four hundred forty-two".