21020266366 has 32 divisors (see below), whose sum is σ = 34587648000. Its totient is φ = 9501806880.

The previous prime is 21020266363. The next prime is 21020266381. The reversal of 21020266366 is 66366202012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020266363) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3021460 + ... + 3028408.

It is an arithmetic number, because the mean of its divisors is an integer number (1080864000).

Almost surely, 2^21020266366 is an apocalyptic number.

21020266366 is a deficient number, since it is larger than the sum of its proper divisors (13567381634).

21020266366 is a wasteful number, since it uses less digits than its factorization.

21020266366 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7704.

The product of its (nonzero) digits is 31104, while the sum is 34.

Adding to 21020266366 its reverse (66366202012), we get a palindrome (87386468378).

The spelling of 21020266366 in words is "twenty-one billion, twenty million, two hundred sixty-six thousand, three hundred sixty-six".