20616666 has 32 divisors (see below), whose sum is σ = 47298048. Its totient is φ = 5868720.

The previous prime is 20616647. The next prime is 20616667. The reversal of 20616666 is 66661602.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20616667) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13161 + ... + 14643.

It is an arithmetic number, because the mean of its divisors is an integer number (1478064).

Almost surely, 2^20616666 is an apocalyptic number.

20616666 is an abundant number, since it is smaller than the sum of its proper divisors (26681382).

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

20616666 is a wasteful number, since it uses less digits than its factorization.

20616666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1826.

The product of its (nonzero) digits is 15552, while the sum is 33.

The square root of 20616666 is about 4540.5578952371. The cubic root of 20616666 is about 274.2033849663.

The spelling of 20616666 in words is "twenty million, six hundred sixteen thousand, six hundred sixty-six".