21020011331 has 4 divisors (see below), whose sum is σ = 22930921464. Its totient is φ = 19109101200.

The previous prime is 21020011321. The next prime is 21020011343. The reversal of 21020011331 is 13311002012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21020011331 is a prime.

It is a super-3 number, since 3×21020011331³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not an unprimeable number, because it can be changed into a prime (21020011321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 955455050 + ... + 955455071.

It is an arithmetic number, because the mean of its divisors is an integer number (5732730366).

Almost surely, 2^21020011331 is an apocalyptic number.

21020011331 is a deficient number, since it is larger than the sum of its proper divisors (1910910133).

21020011331 is a wasteful number, since it uses less digits than its factorization.

21020011331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1910910132.

The product of its (nonzero) digits is 36, while the sum is 14.

Adding to 21020011331 its reverse (13311002012), we get a palindrome (34331013343).

The spelling of 21020011331 in words is "twenty-one billion, twenty million, eleven thousand, three hundred thirty-one".