21213011021 has 8 divisors (see below), whose sum is σ = 22150584960. Its totient is φ = 20276709552.

The previous prime is 21213010999. The next prime is 21213011059. The reversal of 21213011021 is 12011031212.

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 21213011021 - 2⁶ = 21213010957 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21213010987 and 21213011005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213011221) 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, 283961 + ... + 350798.

It is an arithmetic number, because the mean of its divisors is an integer number (2768823120).

Almost surely, 2^21213011021 is an apocalyptic number.

It is an amenable number.

21213011021 is a deficient number, since it is larger than the sum of its proper divisors (937573939).

21213011021 is a wasteful number, since it uses less digits than its factorization.

21213011021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 636235.

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 21213011021 its reverse (12011031212), we get a palindrome (33224042233).

The spelling of 21213011021 in words is "twenty-one billion, two hundred thirteen million, eleven thousand, twenty-one".