666617850 has 120 divisors (see below), whose sum is σ = 1949919840. Its totient is φ = 168389280.

The previous prime is 666617843. The next prime is 666617851. The reversal of 666617850 is 58716666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a junction number, because it is equal to n+sod(n) for n = 666617796 and 666617805.

It is not an unprimeable number, because it can be changed into a prime (666617851) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 72619 + ... + 81281.

It is an arithmetic number, because the mean of its divisors is an integer number (16249332).

Almost surely, 2^666617850 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666617850, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (974959920).

666617850 is an abundant number, since it is smaller than the sum of its proper divisors (1283301990).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

666617850 is a wasteful number, since it uses less digits than its factorization.

666617850 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8706 (or 8692 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 45.

The square root of 666617850 is about 25818.9436267249. The cubic root of 666617850 is about 873.5591415727.

The spelling of 666617850 in words is "six hundred sixty-six million, six hundred seventeen thousand, eight hundred fifty".