1666623417 has 8 divisors (see below), whose sum is σ = 2298791040. Its totient is φ = 1072769040.

The previous prime is 1666623397. The next prime is 1666623419. The reversal of 1666623417 is 7143266661.

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

It is not a de Polignac number, because 1666623417 - 2⁷ = 1666623289 is a prime.

It is a super-2 number, since 2×1666623417² = 5555267228185511778, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1666623419) 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, 9578209 + ... + 9578382.

It is an arithmetic number, because the mean of its divisors is an integer number (287348880).

Almost surely, 2^1666623417 is an apocalyptic number.

It is an amenable number.

1666623417 is a deficient number, since it is larger than the sum of its proper divisors (632167623).

1666623417 is a wasteful number, since it uses less digits than its factorization.

1666623417 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19156623.

The product of its digits is 217728, while the sum is 42.

The square root of 1666623417 is about 40824.2993448755. The cubic root of 1666623417 is about 1185.6208457780.

The spelling of 1666623417 in words is "one billion, six hundred sixty-six million, six hundred twenty-three thousand, four hundred seventeen".