1666121252 has 12 divisors (see below), whose sum is σ = 2916014556. Its totient is φ = 832974240.

The previous prime is 1666121231. The next prime is 1666121291. The reversal of 1666121252 is 2521216661.

It can be written as a sum of positive squares in 2 ways, for example, as 1395321316 + 270799936 = 37354^2 + 16456^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43802 + ... + 72462.

It is an arithmetic number, because the mean of its divisors is an integer number (243001213).

Almost surely, 2^1666121252 is an apocalyptic number.

It is an amenable number.

1666121252 is a deficient number, since it is larger than the sum of its proper divisors (1249893304).

1666121252 is a wasteful number, since it uses less digits than its factorization.

1666121252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43198 (or 43196 counting only the distinct ones).

The product of its digits is 8640, while the sum is 32.

The square root of 1666121252 is about 40818.1485616386. The cubic root of 1666121252 is about 1185.5017552678.

The spelling of 1666121252 in words is "one billion, six hundred sixty-six million, one hundred twenty-one thousand, two hundred fifty-two".