1666613394 has 80 divisors (see below), whose sum is σ = 3971522016. Its totient is φ = 520560000.

The previous prime is 1666613371. The next prime is 1666613437. The reversal of 1666613394 is 4933166661.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 690049 + ... + 692459.

Almost surely, 2^1666613394 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1666613394, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1985761008).

1666613394 is an abundant number, since it is smaller than the sum of its proper divisors (2304908622).

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

1666613394 is a wasteful number, since it uses less digits than its factorization.

1666613394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2693 (or 2684 counting only the distinct ones).

The product of its digits is 419904, while the sum is 45.

The square root of 1666613394 is about 40824.1765869197. The cubic root of 1666613394 is about 1185.6184690160.

The spelling of 1666613394 in words is "one billion, six hundred sixty-six million, six hundred thirteen thousand, three hundred ninety-four".