21020020311 has 8 divisors (see below), whose sum is σ = 29675322864. Its totient is φ = 13189032320.

The previous prime is 21020020291. The next prime is 21020020319. The reversal of 21020020311 is 11302002012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21020020311 - 2⁵ = 21020020279 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020020319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 206078580 + ... + 206078681.

It is an arithmetic number, because the mean of its divisors is an integer number (3709415358).

Almost surely, 2^21020020311 is an apocalyptic number.

21020020311 is a deficient number, since it is larger than the sum of its proper divisors (8655302553).

21020020311 is a wasteful number, since it uses less digits than its factorization.

21020020311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 412157281.

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 21020020311 its reverse (11302002012), we get a palindrome (32322022323).

The spelling of 21020020311 in words is "twenty-one billion, twenty million, twenty thousand, three hundred eleven".