20866406 has 16 divisors (see below), whose sum is σ = 34531920. Its totient is φ = 9377280.

The previous prime is 20866387. The next prime is 20866411. The reversal of 20866406 is 60466802.

It is a happy number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3371 + ... + 7286.

It is an arithmetic number, because the mean of its divisors is an integer number (2158245).

Almost surely, 2^20866406 is an apocalyptic number.

20866406 is a deficient number, since it is larger than the sum of its proper divisors (13665514).

20866406 is a wasteful number, since it uses less digits than its factorization.

20866406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10759.

The product of its (nonzero) digits is 13824, while the sum is 32.

The square root of 20866406 is about 4567.9761382914. The cubic root of 20866406 is about 275.3061318129.

The spelling of 20866406 in words is "twenty million, eight hundred sixty-six thousand, four hundred six".