1666250121 has 8 divisors (see below), whose sum is σ = 2352353184. Its totient is φ = 1045490240.

The previous prime is 1666250107. The next prime is 1666250137. The reversal of 1666250121 is 1210526661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1666250121 - 2⁶ = 1666250057 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1666250101) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16335735 + ... + 16335836.

It is an arithmetic number, because the mean of its divisors is an integer number (294044148).

Almost surely, 2^1666250121 is an apocalyptic number.

It is an amenable number.

1666250121 is a deficient number, since it is larger than the sum of its proper divisors (686103063).

1666250121 is a wasteful number, since it uses less digits than its factorization.

1666250121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32671591.

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 1666250121 is about 40819.7271058982. The cubic root of 1666250121 is about 1185.5323193673.

Adding to 1666250121 its reverse (1210526661), we get a palindrome (2876776782).

The spelling of 1666250121 in words is "one billion, six hundred sixty-six million, two hundred fifty thousand, one hundred twenty-one".