20679666 has 48 divisors (see below), whose sum is σ = 49685760. Its totient is φ = 5715360.

The previous prime is 20679653. The next prime is 20679679. The reversal of 20679666 is 66697602.

It is an interprime number because it is at equal distance from previous prime (20679653) and next prime (20679679).

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7980 + ... + 10248.

It is an arithmetic number, because the mean of its divisors is an integer number (1035120).

Almost surely, 2^20679666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20679666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24842880).

20679666 is an abundant number, since it is smaller than the sum of its proper divisors (29006094).

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

20679666 is a wasteful number, since it uses less digits than its factorization.

20679666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2319 (or 2312 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 42.

The square root of 20679666 is about 4547.4900769545. The cubic root of 20679666 is about 274.4824027127.

The spelling of 20679666 in words is "twenty million, six hundred seventy-nine thousand, six hundred sixty-six".