1666822225 has 6 divisors (see below), whose sum is σ = 2066859590. Its totient is φ = 1333457760.

The previous prime is 1666822211. The next prime is 1666822231. The reversal of 1666822225 is 5222286661.

It can be written as a sum of positive squares in 3 ways, for example, as 120209296 + 1546612929 = 10964^2 + 39327^2 .

It is not a de Polignac number, because 1666822225 - 2⁷ = 1666822097 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 33336420 + ... + 33336469.

Almost surely, 2^1666822225 is an apocalyptic number.

It is an amenable number.

1666822225 is a deficient number, since it is larger than the sum of its proper divisors (400037365).

1666822225 is an equidigital number, since it uses as much as digits as its factorization.

1666822225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66672899 (or 66672894 counting only the distinct ones).

The product of its digits is 138240, while the sum is 40.

The square root of 1666822225 is about 40826.7341946426. The cubic root of 1666822225 is about 1185.6679873088.

The spelling of 1666822225 in words is "one billion, six hundred sixty-six million, eight hundred twenty-two thousand, two hundred twenty-five".