20066391 has 6 divisors (see below), whose sum is σ = 28984800. Its totient is φ = 13377588.

The previous prime is 20066369. The next prime is 20066399. The reversal of 20066391 is 19366002.

It is a happy number.

20066391 is a `hidden beast` number, since 20 + 0 + 6 + 639 + 1 = 666.

It is not a de Polignac number, because 20066391 - 2¹⁸ = 19804247 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20066399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1114791 + ... + 1114808.

It is an arithmetic number, because the mean of its divisors is an integer number (4830800).

Almost surely, 2^20066391 is an apocalyptic number.

20066391 is a deficient number, since it is larger than the sum of its proper divisors (8918409).

20066391 is a wasteful number, since it uses less digits than its factorization.

20066391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2229605 (or 2229602 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 27.

The square root of 20066391 is about 4479.5525446187. The cubic root of 20066391 is about 271.7417847567.

The spelling of 20066391 in words is "twenty million, sixty-six thousand, three hundred ninety-one".